Line-style Bracket extends vertically beyond system

Create a score and place a line-style bracket on a staff/system.
The result has overshooting vertical size of the line instead of, for example, this:

Personally, I think the line bracket has some aesthetic use by thickening the first barline of a measure, especially with a single instrument, without the need for further ornamentation. For instance:

As the program currently is, these images are not capable of being performed in MS. Based on a little conversation in the dev chat, it seems like there's not really a strong standard having to do with the sizing of vertical lines, so I'm going to provide a PR that has the line be equivalent to the system's vertical size rather than "a little bit more" than its size.

I've also noticed a strong lack of use of these line brackets online, so I highly doubt this change would be of any disservice to any current users.