fixed bug in lib/rapidsms/webui/urls.py
fixed bug in lib/rapidsms/webui/urls.py

if an active app didn't have an urls.py (or it raised an import
error), all following apps would fail to load in the webui. erm,
do we have a bug tracker for this stuff?

rapidsms/rapidsms-legacy,rapidsms/rapidsms-legacy,rapidsms/rapidsms-legacy