Fix bindep-fallback.txt for fedora
python-lxml appears to be removed in fedora-25, update to python2-lxml
to fix fedora-25 jobs.
@@ -94,7 +94,8 @@ python-dev [platform:dpkg]
python-devel [platform:rpm]
dev-lang/python [platform:gentoo]
python-libvirt [platform:dpkg]
-python-lxml [!platform:gentoo]
+python-lxml [!platform:gentoo !platform:fedora]
+python2-lxml [platform:fedora]
dev-python/lxml [platform:gentoo]
python-zmq [!platform:gentoo !platform:fedora]
python2-zmq [platform:fedora]
