Corrected a missing argument from the call to DBFlagMismatches()

that causes the recovery option (magic -r) to fail with a segfault
(which is definitely not helpful for recovering lost work).

database/DBio.c

@@ -874,7 +874,7 @@ DBReadBackup(name)
 		return FALSE;
 	    }
 	    /* Update timestamp flags from dbCellReadDef() */
-	    DBFlagMismatches();
+	    DBFlagMismatches(cellDef);
 	}
 	else
 	{