Fix bug 10916: files prefixed with thumb- cause errors.

Rename files that are uploaded to remove thumb-.

lib/WebGUI/Storage.pm

@@ -381,6 +381,7 @@ sub addFileFromFormPost {
         next
             if ($upload->size > 1024 * $self->session->setting->get("maxAttachmentSize"));
         $clientFilename =~ s/.*[\/\\]//;
+        $clientFilename =~ s/^thumb-//;
         my $type = $self->getFileExtension($clientFilename);
         if (isIn($type, qw(pl perl sh cgi php asp html htm))) { # make us safe from malicious uploads
             $clientFilename =~ s/\./\_/g;