Bug#46944 Internal prepared XA transction XIDs are not

removed if server_id changes

When MySQL crashes (or a snapshot is taken which simulates
a crash), then it is possible that internal XA
transactions (used to sync the binary log and InnoDB)
can be left in a PREPARED state, whereas they should be
rolled back.  This is done when the server_id changes
before the restart occurs.  

This patch releases he restriction that the server_id
should be consistent if the XID is to be considerred
valid. The rollback phase should then be able to
clean up all pending XA transactions.

sql/handler.h

@@ -398,7 +398,6 @@ struct xid_t {
   my_xid get_my_xid()
   {
     return gtrid_length == MYSQL_XID_GTRID_LEN && bqual_length == 0 &&
-           !memcmp(data+MYSQL_XID_PREFIX_LEN, &server_id, sizeof(server_id)) &&
            !memcmp(data, MYSQL_XID_PREFIX, MYSQL_XID_PREFIX_LEN) ?
            quick_get_my_xid() : 0;
   }