Chessa::Bug: fix commit check

scripts/Chessa/Bug.pm

@@ -126,7 +126,7 @@ sub parse {
             }
         }
         ($project, $num) = split /$sigil/, $word;
-        if ($sigil eq '@') {
+        if ($type eq 'commit') {
             $num =~ s/^([a-fA-F0-9]+).*/$1/;
         } else {
             $num =~ s/^(\d+).*/$1/;