Revert "MDEV-26223 Galera cluster node consider old server_id value even after modification of server_id [wsrep_gtid_mode=ON]"

This reverts commit a0f711e.

Author: Jan Lindström

mysql-test/suite/galera/r/galera_gtid_server_id.result

@@ -3223,21 +3223,6 @@ static Sys_var_charptr_fscs Sys_secure_file_priv(
        PREALLOCATED READ_ONLY GLOBAL_VAR(opt_secure_file_priv),
        CMD_LINE(REQUIRED_ARG), DEFAULT(0));
 
-static bool check_server_id(sys_var *self, THD *thd, set_var *var)
-{
-#ifdef WITH_WSREP
-  if (WSREP_ON && WSREP_PROVIDER_EXISTS && !wsrep_new_cluster && wsrep_gtid_mode)
-  {
-    push_warning(thd, Sql_condition::WARN_LEVEL_WARN,
-                 ER_WRONG_VALUE_FOR_VAR,
-                 "Can't change server_id because wsrep and wsrep_gtid_mode is set."
-                 " You can set server_id only with wsrep_new_cluster. ");
-    return true;
-  }
-#endif /* WITH_WSREP */
-  return false;
-}
-
 static bool fix_server_id(sys_var *self, THD *thd, enum_var_type type)
 {
   if (type == OPT_GLOBAL)
@@ -3262,7 +3247,7 @@ Sys_server_id(
        "replication partners",
        SESSION_VAR(server_id), CMD_LINE(REQUIRED_ARG, OPT_SERVER_ID),
        VALID_RANGE(1, UINT_MAX32), DEFAULT(1), BLOCK_SIZE(1), NO_MUTEX_GUARD,
-       NOT_IN_BINLOG, ON_CHECK(check_server_id), ON_UPDATE(fix_server_id));
+       NOT_IN_BINLOG, ON_CHECK(0), ON_UPDATE(fix_server_id));
 
 static Sys_var_on_access_global<Sys_var_mybool,
                           PRIV_SET_SYSTEM_GLOBAL_VAR_SLAVE_COMPRESSED_PROTOCOL>

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

@@ -802,6 +802,7 @@ int wsrep_init_server()
 
 void wsrep_init_globals()
 {
+  wsrep_gtid_server.domain_id= wsrep_gtid_domain_id;
   wsrep_init_sidno(Wsrep_server_state::instance().connected_gtid().id());
   /* Recover last written wsrep gtid */
   wsrep_init_gtid();
@@ -816,13 +817,6 @@ void wsrep_init_globals()
     wsrep_get_binlog_gtid_seqno(new_gtid);
     wsrep_gtid_server.gtid(new_gtid);
   }
-  else
-  {
-    if (wsrep_gtid_mode && wsrep_gtid_server.server_id != global_system_variables.server_id)
-    {
-      WSREP_WARN("Ignoring server id for non bootstrap node.");
-    }
-  }
   wsrep_init_schema();
   if (WSREP_ON)
   {