moved C_Timer cancellation in the UNIT_ATTACK_SPEED function

[hypernormalisation]

Cancellations are now in the code block that checks for a valid attack speed change, to avoid cancelling timers when no new timer is going to be set.

This should ensure every START event gets a STOP event even through attack speed changes.

[Ralgathor]

Good catch! For me all is good this can be merged on the main branch.