widthConstraint no longer has any effect

[justinharrell]

After PR #3486 widthConstraint no longer seems to have any effect.

I noticed this in our networks after rebasing and confirmed by navigating to: vis/test/network/maximumWidthEdgeCase.html

Before:

After:

[wimrijnders]

Confirmed. The constraint values were overwritten in the new multifont option handling.