Patch 5.0.0-rc1 version of OMERO formula

As reported in http://www.openmicroscopy.org/community/viewtopic.php?f=6&p=13360#p13360, the OMERO server installed using `brew install omero --devel` currently does not work because we do not patch the version number when passing the `--devel` option.

This commit should fix this issue by patching the 5.0.0-rc1 version of OMERO.  Additionally a checkpoint has been added to the daily OME-*-merge-homebrew jobs to fail if `omero version` returns `UNKNOWN` so that we can catch similar bugs in the future.