[dbapi] Stop shadowing exceptions in get_repository() (closes #2710515)
Exceptions are already handled higher up in the stack so there's no
reason to handle them here. Furthermore, non-ConnectionError exceptions
would get hidden, making debugging harder.
fontcolor = 'black'
bgcolor = '#FFFFFF'
stylesheets = sheet['stylesheets'] + ['%s/mycube.css' % datadir_url]