rpc: Fix help text for signtransactionwithXXX

Author: torkelrogstad

src/rpc/rawtransaction.cpp

@@ -964,7 +964,7 @@ static UniValue signrawtransactionwithkey(const JSONRPCRequest& request)
                                     {"scriptPubKey", RPCArg::Type::STR_HEX, RPCArg::Optional::NO, "script key"},
                                     {"redeemScript", RPCArg::Type::STR_HEX, RPCArg::Optional::OMITTED, "(required for P2SH) redeem script"},
                                     {"witnessScript", RPCArg::Type::STR_HEX, RPCArg::Optional::OMITTED, "(required for P2WSH or P2SH-P2WSH) witness script"},
-                                    {"amount", RPCArg::Type::AMOUNT, RPCArg::Optional::NO, "The amount spent"},
+                                    {"amount", RPCArg::Type::AMOUNT, RPCArg::Optional::OMITTED, "(required for Segwit inputs) the amount spent"},
                                 },
                                 },
                         },

src/wallet/rpcwallet.cpp

@@ -3150,7 +3150,7 @@ UniValue signrawtransactionwithwallet(const JSONRPCRequest& request)
                                     {"scriptPubKey", RPCArg::Type::STR_HEX, RPCArg::Optional::NO, "script key"},
                                     {"redeemScript", RPCArg::Type::STR_HEX, RPCArg::Optional::OMITTED, "(required for P2SH) redeem script"},
                                     {"witnessScript", RPCArg::Type::STR_HEX, RPCArg::Optional::OMITTED, "(required for P2WSH or P2SH-P2WSH) witness script"},
-                                    {"amount", RPCArg::Type::AMOUNT, RPCArg::Optional::NO, "The amount spent"},
+                                    {"amount", RPCArg::Type::AMOUNT, RPCArg::Optional::OMITTED, "(required for Segwit inputs) the amount spent"},
                                 },
                             },
                         },