[devtools] make return value of get_response_header(raw=True) consistent wrt get_header(raw=True)
i.e. get_response_header(raw=True) now returns the first element of the list rather
than the list itself.
debian/tmp/usr/bin/cubicweb-ctl usr/bin/
debian/tmp/usr/lib/PY_VERSION/site-packages/cubicweb/cwctl.py usr/lib/PY_VERSION/site-packages/cubicweb
debian/cubicweb-ctl.bash_completion etc/bash_completion.d/cubicweb-ctl