umdns: update to version 2020-10-26

umdns: update to version 2020-10-26

59e4fc98162d cache: cache_answer: fix off by one
4cece9cc7db4 cache: cache_record_find: fix buffer overflow
be687257ee0b cmake: tests: provide umdns-san binary
bf01f2dd0089 tests: add dns_handle_packet_file tool
134afc728846 tests: add libFuzzer based fuzzing
de08a2c71ca8 cmake: create static library
cdc18fbb3ea8 interface: fix possible null pointer dereference
1fa034c65cb6 interface: fix value stored to 'fd' is never read
3a67ebe3fc66 Add initial GitLab CI support
50caea125517 cmake: fix include dirs and libs lookup

Signed-off-by: Petr Štetiar <ynezz@true.cz>