LaTeX: keep scope of \fboxsep local (#1709)
LaTeX: keep scope of \fboxsep local (#1709)

In case of texcomments=True or usage of escapeinside, arbitrary LaTeX
can be executed. The \PY@bc is executed at top level hence should not
set \fboxsep at this level but keep the change to a local scope.

There is another instance but it is part of PR #1708
dscorbett/pygments,dscorbett/pygments,pygments/pygments,dscorbett/pygments,pygments/pygments,pygments/pygments,dscorbett/pygments,pygments/pygments,dscorbett/pygments,dscorbett/pygments,dscorbett/pygments,pygments/pygments,dscorbett/pygments,dscorbett/pygments,pygments/pygments,pygments/pygments,pygments/pygments,dscorbett/pygments,dscorbett/pygments,pygments/pygments,dscorbett/pygments,dscorbett/pygments,pygments/pygments,pygments/pygments,dscorbett/pygments,dscorbett/pygments,pygments/pygments,dscorbett/pygments,pygments/pygments,pygments/pygments,dscorbett/pygments,pygments/pygments,pygments/pygments,pygments/pygments,pygments/pygments,dscorbett/pygments