[3770_rebase] Clarified what is not sanity-checked.

src/bin/dhcp4/kea-dhcp4.xml

@@ -104,9 +104,11 @@
 
       <varlistentry>
         <term><option>-t</option></term>
-        <listitem><para>
-          Check the syntax of the configuration file (specified with
-          -c) and report the first error if any.
+        <listitem><para> Check the syntax of the configuration file
+          (specified with -c) and report the first error if any. Note
+          that not all parameters are completely checked, in
+          particular, traffic sockets are not opened, control channel
+          socket is not opened and hook libraries are not loaded.
         </para></listitem>
       </varlistentry>
 

src/bin/dhcp6/kea-dhcp6.xml

@@ -105,9 +105,11 @@
 
       <varlistentry>
         <term><option>-t</option></term>
-        <listitem><para>
-          Check the syntax of the configuration file (specified with
-          -c) and report the first error if any.
+        <listitem><para> Check the syntax of the configuration file
+          (specified with -c) and report the first error if any. Note
+          that not all parameters are completely checked, in
+          particular, traffic sockets are not opened, control channel
+          socket is not opened and hook libraries are not loaded.
         </para></listitem>
       </varlistentry>