idevicebackup: try multiple times to lock for sync
idevicebackup: try multiple times to lock for sync

otherwise, the sync in progress screen might keep showing up until you
swipe to cancel on the device

libimobiledevice-win32/libimobiledevice,patweb/libimobiledevice,upbit/libimobiledevice,upbit/libimobiledevice,kalev/libimobiledevice,Tatsh/libimobiledevice,upbit/libimobiledevice,Tatsh/libimobiledevice,Tatsh/libimobiledevice,libimobiledevice-win32/libimobiledevice,Tatsh/libimobiledevice,patweb/libimobiledevice,libimobiledevice-win32/libimobiledevice,libimobiledevice-win32/libimobiledevice,kalev/libimobiledevice,patweb/libimobiledevice,libimobiledevice/libimobiledevice,libimobiledevice/libimobiledevice,kalev/libimobiledevice