00f59d2 rpmbuild: fix custom method for F31's systemd

Authored and Committed by praiskup 4 years ago
    rpmbuild: fix custom method for F31's systemd
    
    Use 'mock --copyin' rather than "mock --shell 'cat -'" for copying files
    into mock buildroot.  This is bugfix caused by changed systemd-nspawn's
    in F31, see https://github.com/rpm-software-management/mock/issues/432.
    
    Fixes: #1123
    Merges: #1124