make missing key error message during SendTransaction more verbose (#…

…1563)

Co-authored-by: 4rgon4ut <[email protected]>

rpc/backend/sign_tx.go

@@ -24,7 +24,7 @@ func (b *Backend) SendTransaction(args evmtypes.TransactionArgs) (common.Hash, e
 	_, err := b.clientCtx.Keyring.KeyByAddress(sdk.AccAddress(args.GetFrom().Bytes()))
 	if err != nil {
 		b.logger.Error("failed to find key in keyring", "address", args.GetFrom(), "error", err.Error())
-		return common.Hash{}, fmt.Errorf("%s; %s", keystore.ErrNoMatch, err.Error())
+		return common.Hash{}, fmt.Errorf("failed to find key in the node's keyring; %s; %s", keystore.ErrNoMatch, err.Error())
 	}
 
 	if args.ChainID != nil && (b.chainID).Cmp((*big.Int)(args.ChainID)) != 0 {