lnwallet: reverse the order of the pubkeys in the funding output

When creating the script for the funding output, we were reversing the
order of the public keys due to an incorrect assertion of the return
value of the bytes.Compare function. To fix this, we now flip the
order, allowing us to properly create channels as specified within the
specification.

lnwallet/script_utils.go

@@ -70,7 +70,7 @@ func genMultiSigScript(aPub, bPub []byte) ([]byte, error) {
 	// order. The signatures within the scriptSig must also adhere to the
 	// order, ensuring that the signatures for each public key appears in
 	// the proper order on the stack.
-	if bytes.Compare(aPub, bPub) == -1 {
+	if bytes.Compare(aPub, bPub) == 1 {
 		aPub, bPub = bPub, aPub
 	}