Restrict factset add_nick to level 10

PBot/FactoidCommands.pm

@@ -39,6 +39,7 @@ my %factoid_metadata_levels = (
   edited_by                   => 60,
   edited_on                   => 60,
   locked                      => 10,
+  add_nick                    => 10,
   # all others are allowed to be factset by anybody/default to level 0
 );
 

PBot/VERSION.pm

@@ -13,7 +13,7 @@ use warnings;
 # These are set automatically by the build/commit script
 use constant {
   BUILD_NAME     => "PBot",
-  BUILD_REVISION => 603,
+  BUILD_REVISION => 604,
   BUILD_DATE     => "2014-05-30",
 };