MDEV-34841 : Enable working Galera tests

* Fixes galera.galera_bf_kill_debug test case.
* Enable galera_ssl_upgrade, galera_ssl_reload, galera_pc_bootstrap
* Add MDEV to disabled tests that miss it
Signed-off-by: Julius Goryavsky <julius.goryavsky@mariadb.com>

mysql-test/suite/galera/t/galera_ssl_upgrade.cnf

 !include ../galera_2nodes.cnf
 
+[mysqld]
+loose-galera-ssl-upgrade=1
+wsrep-debug=1
+
 [mysqld.1]
 wsrep_provider_options='base_port=@mysqld.1.#galera_port;socket.ssl=yes;socket.ssl_cert=@ENV.MYSQL_TEST_DIR/std_data/galera-cert.pem;socket.ssl_key=@ENV.MYSQL_TEST_DIR/std_data/galera-key.pem'
 

mysql-test/suite/galera/t/galera_ssl_upgrade.test

@@ -7,6 +7,8 @@
 --source include/galera_cluster.inc
 --source include/have_innodb.inc
 --source include/have_ssl_communication.inc
+--source include/have_openssl.inc
+--source include/force_restart.inc
 
 # Save original auto_increment_offset values.
 --let $node_1=node_1

mysql-test/suite/galera_3nodes/disabled.def

@@ -11,5 +11,6 @@
 ##############################################################################
 
 galera_2_cluster : MDEV-32631 galera_2_cluster: before_rollback(): Assertion `0' failed
-galera_pc_bootstrap : temporarily disabled at the request of Codership
-galera_ipv6_mariabackup_section : temporarily disabled at the request of Codership
+galera_ipv6_rsync : MDEV-34842 Can't connect to server on '::1' (115)
+galera_ipv6_rsync_section : MDEV-34842 Can't connect to server on '::1' (115)
+galera_ipv6_mariabackup_section : MDEV-34842 Can't connect to server on '::1' (115)