Fix queue behaviour when switching away from random

[bivhitscar]

Playback should proceed according to the currently selected queue behaviour. The implementation of random/shuffle was causing other options to fail if it had been previously selected.

This change restores the actual playlist position when switching queue behaviours, allowing for correct queue advancement at the end of the currently playing item.

To reproduce the original problem:
Open a playlist/album.
Select and play any item other than number 1*.
Select the random queue behaviour.
Select the loop all behaviour.
Click the skip to next item button.
When play advances to the next item, it will not be as expected (item 2 will probably play).

*The problem still exists from here, but is harder to spot.