Form overlay links are broken if fetching ++form++ doesn't work

[Paul Hummer]

I just had a weird anomaly with javascript on the "Link a bug" functionality while redesigning the branch index page. Basically, the form overlay widget tried to get its ++form++ representation, but an error occurred while doing it. I'm still not sure if this is broken across the board or just something I'm doing currently, but that is orthagonal to the issue at hand.

The real issue is that since the form fetching hicupped, the functionality is completely broken. The fix is that if the form fetching doesn't work, we don't attach the javascript event to the link at all.