Fix the user input for "Port"

Port can be something not listed in the combobox, like
tcp:192.168.xxx.xxx:xxxxx(25 characters)
bt:aa:bb:cc:dd:ee:ff(20 characters)

src/ui/mainwindow.cpp

@@ -158,7 +158,15 @@ void MainWindow::on_PM3_connectButton_clicked()
 {
     qDebug() << "Main:" << QThread::currentThread();
 
-    QString port = ui->PM3_portBox->currentData().toString();
+    const QComboBox* portBox = ui->PM3_portBox;
+    QString port;
+    if(portBox->currentText() == portBox->itemText(portBox->currentIndex()))
+        // in the list
+        port = portBox->currentData().toString();
+    else
+        // not in the list
+        port = portBox->currentText();
+    qDebug() << "port:" << port;
     QString startArgs = ui->Set_Client_startArgsEdit->text();
     QString clientPath = ui->PM3_pathBox->currentText();
     QFileInfo clientFile(clientPath);

src/ui/mainwindow.ui

@@ -94,6 +94,9 @@
         <property name="editable">
          <bool>true</bool>
         </property>
+        <property name="minimumContentsLength">
+         <number>15</number>
+        </property>
        </widget>
       </item>
       <item>