Default (first) scroll should respect our settings

[ttodua]

fixes #939

eg. if you set 15 as step-size, that step-size is only respected before "Volume Indicator" window appears (maybe around several hundred MS timespan). After it's shown, then next scrolls would be still 2.

I understand this might not be ideal solution, but better than hardcoded 2, and i would even say that this solution would fix for most users, because I can quickly turn volume from 10 to 100 in one quick scroll (before Indicator appears, while we have step-size eg. 20 in settings). otherwise, we have to make around 10 scrolls. so, this is a huge difference, and actually solution.

so, this won't be breaking solution for any users, because if users want consistent 2 then they just choose 2 in settings and that's all. but if we want 20 then we would benefit of this PR.