Correct path for fedmsg-functions.
    
    Looks like this broke.  See the cron logs for:
    
        ./scripts/build-functions.sh: line 63: fedmsg-functions.sh: No such file or directory
    
    https://lists.fedoraproject.org/archives/list/releng-cron%40lists.fedoraproject.org/thread/THAQMLHQFOVJLWXTRJIAXJOY3O7T4PA5/
    
    Signed-off-by: Ralph Bean <rbean@redhat.com>