Fix mouse reports
Fix mouse reports

The patch 9cb5562 has introduced a regression which would abort if a
mouse report's line was bigger than zero, which is the exact opposite of
when a mouse report is required.

Fixes #4980.
jwilm/alacritty,alacritty/alacritty,alacritty/alacritty,jwilm/alacritty,jwilm/alacritty,jwilm/alacritty