Using libmtp or libgphoto2 to access a device that gvfs has mounted causes the
connection to fail. libmtp is calling libusb_claim_interface which, according to
libusb documentation, will return LIBUSB_ERROR_BUSY if claimed by a different
program. For mtp and gphoto2 devices discovered by the GioLister, use the file
scheme and access the device through the gvfs mount.
The uri returned from g_file_get_uri is percent encoded. This causes the regex
in GioLister::MakeDeviceUrls to fail and causes the URL to be invalid. In this
case, it falls back to the file scheme. Newer versions of gvfs obtain the serial
id from udev instead of using the bus and device IDs.
Note that this bug covers a different issue where mtp is failing to connect. The
result is actually desired behavior. The follow-up change will address this.