MDEV-12353: Remove a trace of pre-MDEV-13564 crash-upgrade

In commit f8a9f906
we removed support for crash-upgrade from older versions,
but forgot to remove a check for recovering TRUNCATE TABLE
if MariaDB 10.2.18 or 10.3.9 or earlier were killed and
we are attempting to upgrade to MariaDB 10.5.2 or later.
Already MariaDB 10.4 would refuse to recover such TRUNCATE
operations.

storage/innobase/log/log0recv.cc

@@ -2535,17 +2535,6 @@ void recv_apply_hashed_log_recs(bool last_batch)
 
 	if (recv_sys.pages.empty()) {
 		goto done;
-	}
-
-	if (!log_sys.log.subformat && !srv_force_recovery
-	    && srv_undo_tablespaces_open) {
-		ib::error() << "Recovery of separately logged"
-			" TRUNCATE operations is no longer supported."
-			" Set innodb_force_recovery=1"
-			" if no *trunc.log files exist";
-		recv_sys.found_corrupt_log = true;
-		mutex_exit(&recv_sys.mutex);
-		return;
 	} else {
 		const char* msg = last_batch
 			? "Starting final batch to recover "