Record demoes to a different filename after backup restoration

[TandelK]

If there is a server crash and we load the last backup file , the Demo recording doesnt work properly as it has already same name file in the directory. There should be a condition for backup loading and demo recording if the backup command is used , it should the new file with _backup.demo in the end making it clear for 2 different demos one before crash and one after backup loaded.