Hidden label when using position: "top" on vertical line label

[buejoh]

Version: 0.5.3

Using position: "top" results in a hidden label when using vertical line annotation.

Changing line 852 in the source code from

ret.x = (isFinite(line.m) ? line.getY(ret.y) : view.x1) - xa;

to

ret.x = (isFinite(line.m) ? line.getX(ret.y) : view.x1) - xa;

fixes this issue. Maybe just a typo?

[compwright]

I believe so, yes. Feel free to submit a PR.