Disable static user mode build on RHEL
The ELN stream builds Fedora packages in a psuedo-RHEL build root and
does not ship all the things that Fedora expects to be present. In
particular glib2-static is missing in ELN build roots, so we need to
disable the user mode static build.
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>