Dont setCurrentIndex on serial port combo

Something got weird and then broke (PySide6-Essentials 6.6.1, 6.6.3)
with QComboBox and trying to use the setCurrentIndex slot in another
thread gives

QBasicTimer::start: Timers cannot be started from another thread
QObject::startTimer: Timers cannot be started from another thread

errors when selecting the combo box afterwards. This was just a QoL
feature so just remove it.

OATFWGUI/gui_logic.py

@@ -361,11 +361,6 @@ def pio_refresh_ports_finished(self):
         self.main_app.wCombo_serial_port.clear()
         for serial_port in self.logic_state.serial_ports:
             self.main_app.wCombo_serial_port.addItem(serial_port)
-        if len(self.logic_state.serial_ports) > 0:
-            self.main_app.wCombo_serial_port.setCurrentIndex(0)
-        else:
-            self.logic_state.upload_port = None
-            self.main_app.wCombo_serial_port.setCurrentIndex(-1)
 
     @Slot()
     def serial_port_combo_box_changed(self, idx: int):