[trac1732] datasource type is required

This was copied from manpage so fix there.

Noticed by jelte. And I confirmed:

2012-03-28 11:07:43.931 ERROR [b10-auth.auth] AUTH_CONFIG_UPDATE_FAIL update of configuration failed: Missing data source type

doc/guide/bind10-guide.xml

@@ -1326,7 +1326,7 @@ This may be a temporary setting until then.
               <simpara>
       <varname>datasources</varname> configures data sources.
       The list items include:
-      <varname>type</varname> to optionally choose the data source type
+      <varname>type</varname> to define the required data source type
       (such as <quote>memory</quote>);
       <varname>class</varname> to optionally select the class
       (it defaults to <quote>IN</quote>);

src/bin/auth/b10-auth.xml

@@ -20,7 +20,7 @@
 <refentry>
 
   <refentryinfo>
-    <date>March 1, 2012</date>
+    <date>March 28, 2012</date>
   </refentryinfo>
 
   <refmeta>
@@ -119,7 +119,7 @@
     <para>
       <varname>datasources</varname> configures data sources.
       The list items include:
-      <varname>type</varname> to optionally choose the data source type
+      <varname>type</varname> to define the required data source type
       (such as <quote>memory</quote>);
       <varname>class</varname> to optionally select the class
       (it defaults to <quote>IN</quote>);