kojipkgs: slightly relax openh264 blocking/redirect rules
    
    Allow access to gstreamer1-plugin-openh264 package and new noopenh264
    stub package that don't contain non-distributable code, while keeping
    openh264* and mozilla-openh264* blocked.
    
    See https://bugzilla.redhat.com/bugzilla/show_bug.cgi?id=2247274 for
    "noopenh264" stub package review that makes it possible to build/ship
    the gstreamer plugin in Fedora proper while keeping the
    non-distributable openh264 package in Cisco repos.