Correct the merge 0f83c887

Re-enable some Galera tests that should have been enabled.

Add client_ed25519.so to debian/libmariadb3.install;
merge e47a143f correctly.

Remove a duplicated #include from wsrep_mysqld.cc.

debian/libmariadb3.install

@@ -3,3 +3,4 @@ usr/lib/mysql/plugin/client_ed25519.so
 usr/lib/mysql/plugin/dialog.so
 usr/lib/mysql/plugin/mysql_clear_password.so
 usr/lib/mysql/plugin/sha256_password.so
+usr/lib/mysql/plugin/client_ed25519.so

mysql-test/suite/galera/disabled.def

@@ -25,12 +25,7 @@ galera_gcache_recover_manytrx : MDEV-18834 Galera test failure
 galera_ist_mariabackup : MDEV-18829 test leaves port open
 galera_ist_progress : MDEV-15236 fails when trying to read transfer status
 galera_migrate : MariaDB does not support START SLAVE USER
-galera_pc_ignore_sb : MDEV-15811/MDEV-17357 Test failure
-galera_ssl_upgrade : MDEV-13549 Galera test failures
-galera_sst_mysqldump_with_key : MDEV-16890 Galera test failure
-galera_var_node_address : MDEV-17151 Galera test failure
-galera_var_notify_cmd : MDEV-13549 Galera test failures
-galera_var_slave_threads : MDEV-19746 Galera test failures because of wsrep_slave_threads identification
+galera_ssl_upgrade : MDEV-19950 Galera test failure on galera_ssl_upgrade
 galera_var_node_address : MDEV-20485 Galera test failure on galera.galera_var_node_address
 galera_wan : MDEV-17259 Test failure on galera.galera_wan
 partition : MDEV-19958 Galera test failure on galera.partition

mysql-test/suite/wsrep/disabled.def

@@ -11,4 +11,3 @@
 ##############################################################################
 
 foreign_key : Sporadic failure "WSREP has not yet prepared node for application use"
-variables : MDEV-19746 Galera test failures because of wsrep_slave_threads identification

sql/wsrep_mysqld.cc

@@ -38,7 +38,6 @@
 #include <cstdlib>
 #include "log_event.h"
 #include <slave.h>
-#include "sql_plugin.h"                         /* wsrep_plugins_pre_init() */
 
 wsrep_t *wsrep                  = NULL;
 /*