allows manual BLE pin even when device has display

also updates remaining variants to use default of
123456 instead of 0 for random pin

variants/nano_g2_ultra/platformio.ini

@@ -36,7 +36,7 @@ build_flags =
   -I src/helpers/ui
   -D MAX_CONTACTS=100
   -D MAX_GROUP_CHANNELS=8
-  -D BLE_PIN_CODE=0
+  -D BLE_PIN_CODE=123456
   -D BLE_DEBUG_LOGGING=1
   -D OFFLINE_QUEUE_SIZE=256
   -D DISPLAY_CLASS=SH1106Display