Remove "design for extension" from checkstyle checks

git-svn-id: http://svn.dmdirc.com/trunk@3964 00569f92-eb28-0410-84fd-f71c24880f

checkstyle/dmdirc_checks.xml

@@ -154,7 +154,7 @@
 
         <!-- Checks for class design                         -->
         <!-- See http://checkstyle.sf.net/config_design.html -->
-        <module name="DesignForExtension"/>
+        <!-- <module name="DesignForExtension"/> -->
         <module name="FinalClass"/>
         <module name="HideUtilityClassConstructor"/>
         <module name="InterfaceIsType"/>