[devtools] Fix database creation issues for CubicWebTestTC tests
To reproduce (with a purged repo):
* python web/test/test_jscript.py
* python web/test/unittest_views_xmlrss.py
The '__default_empty_db__' will contain the wrong 'base_url'
configuration, thus breaking URLs in the xmlrss tests.
Closes #9297611.
usr/lib/python2*/*-packages/cubicweb/devtools/
usr/lib/python2*/*-packages/cubicweb/skeleton/
usr/lib/python2*/*-packages/cubicweb/test
usr/lib/python2*/*-packages/cubicweb/dataimport/test
usr/lib/python2*/*-packages/cubicweb/entities/test
usr/lib/python2*/*-packages/cubicweb/ext/test
usr/lib/python2*/*-packages/cubicweb/server/test
usr/lib/python2*/*-packages/cubicweb/sobjects/test
usr/lib/python2*/*-packages/cubicweb/hooks/test
usr/lib/python2*/*-packages/cubicweb/web/test
usr/lib/python2*/*-packages/cubicweb/etwist/test