ERP5: disable unused beta plugin handlersocket in MariaDB

Since we moved to MariaDB 10.3, that's actually already the case
because of --plugin-maturity=gamma

stack/erp5/buildout.hash.cfg

@@ -42,7 +42,7 @@ md5sum = d32417746fcf671d4e86a70379815039
 
 [template-my-cnf]
 filename = my.cnf.in
-md5sum = 2e381fb10a7c024c99caa434036173c6
+md5sum = af2113bbdeaf32096c4013fa73b45ced
 
 [template-mariadb-initial-setup]
 filename = mariadb_initial_setup.sql.in

stack/erp5/my.cnf.in

@@ -29,7 +29,7 @@ max_allowed_packet = 128M
 query_cache_size = 32M
 innodb_file_per_table = 0
 
-plugin_load = ha_mroonga.so;handlersocket.so
+plugin_load = ha_mroonga
 
 # By default only 100 connections are allowed, when using zeo
 # we may have much more connections