remove variable_ in headers just so its consistent

git-svn-id: http://svn.freeswitch.org/svn/freeswitch/trunk@16925 d0543943-73ff-0310-b7d9-9358b9ac24b2

libs/esl/perl/ESL/Dispatch.pm

@@ -53,6 +53,7 @@ sub render_event($;$$) {
     if ($self->{_decode}) {
       $val =~ s/\%([A-Fa-f0-9]{2})/pack('C', hex($1))/seg;
     }
+    $h =~ s/^variable_//;
     $self->{event_hash}->{lc($h)} = $val;
     $h = $event->nextHeader();
   }