CVE-2021-2166 (DoS).
Various hash_XXX functions have been renamed to ma_hashtbl_XXX to fix
an issue with static linking to newer GnuTLS releases;
https://jira.mariadb.org/browse/CONC-543
d19c7c6926
These functions don't appear to be in the exported API so I have skipped
bumping the library version so that the same update can be used in stable.
I don't expect problems but if we run into any it can be bumped later.