This is similar to I0966786226d3f534a7f326d9df2cd73e7e3749dd
ansible_distribution may return a string with spaces such as "openSUSE
Leap" so we need to replace the space with underscore in order to create a
more sensible repo name for the distro.
Change-Id: If653232b1bc51a3429875bc21ea88dba594423df