Spielpartner im Urlaub
Since only 1 move has been played, I think you can abort the game. Hover your cursor over the options and see if it says Resign or Abort.
Other than that, you can just wait until your opponent comes back and makes a move or runs out of vacation. The game won't be rated if timed out, since there aren't enough moves so it really won't impact anything to have it be in that state.