multi: remove litecoin references and comments

chanrestore.go

@@ -227,8 +227,8 @@ func (c *chanDBRestorer) RestoreChansFromSingles(backups ...chanbackup.Single) e
 
 		default:
 			// Worst case: We have no height hint and start at
-			// block 1. Should only happen for SCBs in regtest,
-			// simnet and litecoin.
+			// block 1. Should only happen for SCBs in regtest
+			// and simnet.
 			firstChanHeight = 1
 		}
 	}