This affects more than src/Makefile.am as the rule to generate source
files for protocols is generic for all sub-directories.

Affected files are:
    src/admin/admin_protocol.{h,c}
    src/locking/lock_protocol.{h,c}
    src/logging/log_protocol.{h,c}
    src/lxc/lxc_monitor_protocol.{h,c}
    src/remote/{lxc,qemu,remote}_protocol.{h,c}
    src/rpc/{virkeepalive,virnet}protocol.{h,c}
Signed-off-by: NPavel Hrdina <phrdina@redhat.com>
Reviewed-by: NJán Tomko <jtomko@redhat.com>
Reviewed-by: NDaniel P. Berrangé <berrange@redhat.com>