remove variable that is always equal to 0

[sorokin]

No description provided.

[eteran]

I'm not sure that it's a benefit to remove this particular variable. While there is nothing to the left of "line 0", there could one day be, so having it be a tunable parameter seems to at the very least, do no harm.

[sorokin]

Let me explain why I decided to remove this variable.

I wanted to fix #752 by making separate settings for line{1,2,3,4} for 32- and 64-bit modes. Apparently line{1,2,3,4} are saved to settings while line0 is not. So I decided to remove this asymmetry are removed line0.

But you are right for now line0 can stay.

[eteran]

Gotcha makes sense about the settings. Thanks for your efforts in fixing these bugs.

I'm going to close this PR, if it turns out that in the future, there is a tangible benefit to removing this variable, feel free to open another :-).