Remove package mapping for mariadb-rdo-galera-server

This mapping is not needed anymore because mariadb-rpm element
(renamed from mariadb-rdo) uses pkg-map.

Relies on: I90e7ca4803516b86179b0f6639e307a60297960b
Change-Id: I19fb44ee6008c6c57dd331a780eec3234d46b15c
Merge "Remove package mapping for mariadb-rdo-galera-server"