Drop the line after box warnings
Drop the line after box warnings

The first line after a box warning is just garbage. So, we drop it as it
may contain '(' or ')', which interfere with the computation of the
Latex files stack.

It is related to #730 (Issue 2).

James-Yu/LaTeX-Workshop,James-Yu/LaTeX-Workshop,James-Yu/LaTeX-Workshop,James-Yu/LaTeX-Workshop,James-Yu/LaTeX-Workshop