Fix thinko in re-setting wal_log_hints flag from a parameter-change record.

The flag is supposed to be copied from the record. Same issue with
track_commit_timestamps, but that's master-only.

Report and fix by Petr Jalinek. Backpatch to 9.4, where wal_log_hints was
added.

Author: hlinnaka

src/backend/access/transam/xlog.c

@@ -9415,7 +9415,7 @@ xlog_redo(XLogRecPtr lsn, XLogRecord *record)
 		ControlFile->max_prepared_xacts = xlrec.max_prepared_xacts;
 		ControlFile->max_locks_per_xact = xlrec.max_locks_per_xact;
 		ControlFile->wal_level = xlrec.wal_level;
-		ControlFile->wal_log_hints = wal_log_hints;
+		ControlFile->wal_log_hints = xlrec.wal_log_hints;
 
 		/*
 		 * Update minRecoveryPoint to ensure that if recovery is aborted, we