calcby set after textfield changed

GMERemittance/Module/ExchangeRateViewControllerV2.swift

@@ -197,11 +197,11 @@ class ExchangeRateViewControllerV2: UIViewController {
     @objc private func textChanged(sender: UITextField) {
         switch sender {
         case senderTextField:
-            self.calcBy = "c"
             self.reciepientTextField.text = ""
+            self.calcBy = "c"
         case reciepientTextField:
-            self.calcBy = "p"
             self.senderTextField.text = ""
+            self.calcBy = "p"
         default:
             break
         }