[BUG] LineSeries and draw_series go out of the image scope if stroke_width > 1

[fitz35]

Describe the bug
Describe what is expected, what you actually get.
It would be nice to have screenshot or result image uploaded
When using draw_series and LineSeries with BitMapBackend on highly variable data, augmenting the stroke width made the line to go out of the image. The following graph is plotted with a stroke width of 2 :

The same graphic with a stroke width of 1 :

NOTE : The change of color is because I use a HashMap to plot the serie.
To Reproduce
Some minimal reproduce code is highly recommended

I can export data which are "highly variable", but I'm not sure how to give access to it. Here is the code I use :

// stroke width 1
chart
                .draw_series(
                    LineSeries::new(
                        data_for_legend.iter().map(|(x, y)| (*x, *y)),
                        color.filled().stroke_width(1)
                    )
                )?;

// stroke width 2
chart
                .draw_series(
                    LineSeries::new(
                        data_for_legend.iter().map(|(x, y)| (*x, *y)),
                        color.filled().stroke_width(2)
                    )
                )?;

Version Information
Please give us what version you are using. If you are pulling Plotters directly from git repo, please mention this as well
The version I use is the 0.3.3.