cobbler.spec - don't overwrite generated files

Commits f550ad5485430ee7c6bd7554a0fe4a45456d7b49 and
9eb1f39df9d9c430cc30fadd271a6df69f21ce43, changed the httpd/*.conf
and cobblerd.service files to be generated. Include the
generated versions into the rpms.
Merge pull request #684 from mark987/fix-rpm-httpd

cobbler.spec - don't overwrite generated httpd files