remove double words

doc/guide/admin.xml

@@ -36,7 +36,7 @@
       a <replaceable>major.minor</replaceable> format. The minor
       number is increased when there are backward compatibile changes
       introduced.  For example, the addition of a new index. It is
-      desirable, but not mandatory to to apply such a change; you
+      desirable, but not mandatory to apply such a change; you
       can run on older database version if you want to. (Although, in
       the example given, running without the new index may be at the
       expense of a performance penalty.) On the other hand, the major

doc/guide/ddns.xml

@@ -136,7 +136,7 @@ strings <userinput>path</userinput>/kea-dhcp-ddns | sed -n 's/;;;; //p'
         <itemizedlist>
             <listitem>
             <simpara><command>localstatedir</command>: The value as passed into the
-            build configure script. It defaults defaults to "/usr/local/var".  Note
+            build configure script. It defaults to "/usr/local/var".  Note
             that this value may be overridden at run time by setting the environment
             variable KEA_PIDFILE_DIR.  This is intended primarily for testing purposes.
             </simpara>

doc/guide/dhcp4-srv.xml

@@ -113,7 +113,7 @@ strings <userinput>path</userinput>/kea-dhcp4 | sed -n 's/;;;; //p'
         <itemizedlist>
             <listitem>
             <simpara><command>localstatedir</command>: The value as passed into the
-            build configure script. It defaults defaults to "/usr/local/var".  Note
+            build configure script. It defaults to "/usr/local/var".  Note
             that this value may be overridden at run time by setting the environment
             variable KEA_PIDFILE_DIR.  This is intended primarily for testing purposes.
             </simpara>

doc/guide/dhcp6-srv.xml

@@ -111,7 +111,7 @@ strings <userinput>path</userinput>/kea-dhcp6 | sed -n 's/;;;; //p'
         <itemizedlist>
             <listitem>
             <simpara><command>localstatedir</command>: The value as passed into the
-            build configure script. It defaults defaults to "/usr/local/var".  Note
+            build configure script. It defaults to "/usr/local/var".  Note
             that this value may be overridden at run time by setting the environment
             variable KEA_PIDFILE_DIR.  This is intended primarily for testing purposes.
             </simpara>
@@ -2169,7 +2169,7 @@ should include options from the isc option space:
     that has specific requirements, e.g. a printer that needs additional DHCP options
     or a cable modem needs specific parameters. Yet another possible use case for
     host reservation is to define unique names for hosts.  Although not all of
-    the presented use cases are are implemented yet, Kea software will support them
+    the presented use cases are implemented yet, Kea software will support them
     in the near future.</para>
 
     <para>Hosts reservations are defined as parameters for each subnet. Each host
@@ -2327,7 +2327,7 @@ should include options from the isc option space:
       <para>When the reservation for the client includes the <command>hostname
       </command>, the server will assign this hostname to the client and send
       it back in the Client FQDN, if the client sent the FQDN option to the
-      the server. The reserved hostname always takes precedence over the hostname
+      server. The reserved hostname always takes precedence over the hostname
        supplied by the client (via the FQDN option) or the autogenerated
       (from the IPv6 address) hostname.</para>
 

doc/guide/lfc.xml

@@ -72,7 +72,7 @@ kea-lfc [-4 | -6] -c config-file -p pid-file -x previous-file -i copy-file -o ou
           <listitem><simpara>
             <command>output</command> &mdash;
             The temporary file <command>kea-lfc</command> should use to write the leases.
-            Upon completion of writing this this file it will be moved to the finish file
+            Upon completion of writing this file, it will be moved to the finish file
            (see below).
           </simpara></listitem>