MDEV-33837: Remove unneeded lintian override in libmariadb-dev

There is unused override which is not needed an polluting
output

 * unused-override arch-dependent-file-not-in-arch-specific-directory usr/bin/mariadb_config [usr/share/lintian/overrides/libmariadb-dev:2]

debian/libmariadb-dev.lintian-overrides

-# This is how upstream does it, wont' fix
-arch-dependent-file-not-in-arch-specific-directory usr/bin/mariadb_config
-
 # Needed conflict
 conflicts-with-version libmariadb-dev-compat (<< 3.0.0)