rpc: Remove duplicate field in RPCHelpMan for gettransactions

The field 'comment' appears twice in TransactionDescriptionString,
incorrectly - this commit removes the instance of the comment field
without a description, preserving the one with a description

Author: jdjkelly

src/wallet/rpc/transactions.cpp

@@ -416,7 +416,6 @@ static const std::vector<RPCResult> TransactionDescriptionString()
            }},
            {RPCResult::Type::STR_HEX, "replaced_by_txid", /*optional=*/true, "The txid if this tx was replaced."},
            {RPCResult::Type::STR_HEX, "replaces_txid", /*optional=*/true, "The txid if the tx replaces one."},
-           {RPCResult::Type::STR, "comment", /*optional=*/true, ""},
            {RPCResult::Type::STR, "to", /*optional=*/true, "If a comment to is associated with the transaction."},
            {RPCResult::Type::NUM_TIME, "time", "The transaction time expressed in " + UNIX_EPOCH_TIME + "."},
            {RPCResult::Type::NUM_TIME, "timereceived", "The time received expressed in " + UNIX_EPOCH_TIME + "."},