bug#51264: MySQL.prefPane fails to run
bug#51264: MySQL.prefPane fails to run

@prefix@ was erroneously set to '.' with the STANDALONE install
layout, when it should instead be set to CMAKE_INSTALL_PREFIX,
this was likely accidentally copied from scripts/CMakeLists.txt
which has similar handling specifically for mysql_install_db.sh

mysql.server init script can now find the install, assuming the
defaults have been chosen.

davidl-zend/zenddbi,flynn1973/mariadb-aix,ollie314/server,natsys/mariadb_10.2,davidl-zend/zenddbi,ollie314/server,ollie314/server,flynn1973/mariadb-aix,ollie314/server,natsys/mariadb_10.2,davidl-zend/zenddbi,natsys/mariadb_10.2,flynn1973/mariadb-aix,natsys/mariadb_10.2,ollie314/server,natsys/mariadb_10.2,davidl-zend/zenddbi,davidl-zend/zenddbi,natsys/mariadb_10.2,ollie314/server,flynn1973/mariadb-aix,natsys/mariadb_10.2,flynn1973/mariadb-aix,ollie314/server,ollie314/server,natsys/mariadb_10.2,davidl-zend/zenddbi,natsys/mariadb_10.2,davidl-zend/zenddbi,ollie314/server,flynn1973/mariadb-aix,natsys/mariadb_10.2,flynn1973/mariadb-aix,flynn1973/mariadb-aix,flynn1973/mariadb-aix,natsys/mariadb_10.2,davidl-zend/zenddbi,slanterns/server,davidl-zend/zenddbi,flynn1973/mariadb-aix,davidl-zend/zenddbi,davidl-zend/zenddbi,ollie314/server,ollie314/server,flynn1973/mariadb-aix