memory, by removing the priority field of Matching_info.
* src/libraries/libcommon/parser.c (parse): Don't let the priority
influence the match.  The priority functionality was poorly
documented, not used by lyskomd, and made the code more complex.
* src/libraries/libcommon/parser.h (Matching_info): Removed the
priority field, which is no longer used.
* src/server/simple-cache.c (rebuild_matching_info_entry): Don't
initialize the priority field.
(build_matching_info): Ditto.