Set Content only when a value is returned from transactions

Previously if an Incident had no content in the Create
transaction, TransactionData would return undef, setting
$ARGS{Content} to undef. This would cause the message box to show
the string "null" rather than the default empty placeholder
text.

Author: cbrandtbuffalo

html/RTIR/Create.html

@@ -174,14 +174,18 @@
         if ( RT::IR->IsInvestigationQueue($QueueObj) ) {
             $quote = 1;
         }
-        $ARGS{Content} = $m->scomp(
+        my $starting_content = $m->scomp(
             "/RTIR/Elements/TransactionData",
             Transactions => $Transactions,
             Type         => 'messages',
             Include      => { 'Create', 'Correspond' },
             QuoteText    => $quote,
         );
-        $ARGS{Content} =~ s/\>/>/g if $ARGS{Content};
+
+        if ( $starting_content ) {
+           $starting_content =~ s/\>/>/g;
+           $ARGS{Content} = $starting_content;
+       }
     }
 }