Fix 500 page, fix timeouts, fix access issue

* the 500 page could use some more help
* this increases requests timeouts to bugzilla to 60 seconds which
  should cover most searches
* if the user has no access to view a depends_on bug which blocks a bug
  they can see, then it doesn't show up in the id_to_status dict and
  then it throws an error; I wrapped that in a try/except with a
  comment, but I'm not sure what to do in this case