OpenMTP doesn't handle multiple devices well

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Prerequisites

• Have you reviewed the steps in the following link to see if they address your issue?
  • Just a blank screen or MTP device is not recognized #276

Describe the bug
When launching OpenMTP with multiple MTP devices connected, the software displays the "FAQS - MY PHONE IS NOT CONNECTING!" information page. There is also a red box that says "Multiple MTP devices found" in the top right hand corner of the screen, but this disappears after about three seconds.

Disconnecting one of the devices resolved the problem. I acknowledge that handling multiple devices properly would require a significant rework of the user interface; but at the very least, the "Multiple MTP devices found" alert should hang around until explicitly dismissed by the user.

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The two devices in this specific case were a Garmin Edge 540 (with the latest firmware - I'm a little annoyed at Garmin making this change) and a Fenix 7s. However, I would expect it to be reproducible with any two MTP devices connected simultaneously.