shell - fsop, incorrect restarting of progress window timeout after error

[rozniak]

Noticed an oversight with the logic for pausing/restarting the timeout for the copy/move progress dialog. If there's no window displayed yet, the timeout should be paused until the error is cleared. ATM it restarts the timer without checking if it was paused:

https://github.com/rozniak/xfce-winxp-tc/blob/master/shared/shell/src/fsop.c#L649

Need to track whether the timer was just paused. Checking if the timeout id is 0 won't do the job because it will be 0 once the progress window has spawned.