Vesctool otg

Would be a nice addition to the mobile app to have the option to use my phone to connect to the USB otg for firmware or setting changes instead of my laptop as it's a always a rock solid connection.

My experience with the BT function is hit and miss, sometimes I have no end of trouble just trying simple changes, I'm resorting to installing some micro USB extensions and tucking them away outside the enclosure. I'm getting over the BT function, I didn't notice this before with 5.2 but I do with 5.3.