update some strings used as warning messages in sendcoinsdialog.cpp

src/qt/sendcoinsdialog.cpp

@@ -130,23 +130,23 @@ void SendCoinsDialog::on_sendButton_clicked()
         break;
     case WalletModel::AmountExceedsBalance:
         QMessageBox::warning(this, tr("Send Coins"),
-            tr("Amount exceeds your balance"),
+            tr("The amount exceeds your balance."),
             QMessageBox::Ok, QMessageBox::Ok);
         break;
     case WalletModel::AmountWithFeeExceedsBalance:
         QMessageBox::warning(this, tr("Send Coins"),
-            tr("Total exceeds your balance when the %1 transaction fee is included").
+            tr("The total exceeds your balance when the %1 transaction fee is included.").
             arg(BitcoinUnits::formatWithUnit(BitcoinUnits::BTC, sendstatus.fee)),
             QMessageBox::Ok, QMessageBox::Ok);
         break;
     case WalletModel::DuplicateAddress:
         QMessageBox::warning(this, tr("Send Coins"),
-            tr("Duplicate address found, can only send to each address once in one send operation"),
+            tr("Duplicate address found, can only send to each address once per send operation."),
             QMessageBox::Ok, QMessageBox::Ok);
         break;
     case WalletModel::TransactionCreationFailed:
         QMessageBox::warning(this, tr("Send Coins"),
-            tr("Error: Transaction creation failed  "),
+            tr("Error: Transaction creation failed."),
             QMessageBox::Ok, QMessageBox::Ok);
         break;
     case WalletModel::TransactionCommitFailed: