gitignore: Add generated *.pot files in po/ subdirectory
gitignore: Add generated *.pot files in po/ subdirectory

flaxandteal/gasket-vte,saitoha/vte-sixel,pjm0616/vte,flaxandteal/gasket-vte,gloob/vte-copy,jessevdk/vte,gloob/vte-copy,asivokon/vte-fx,asivokon/vte-fx,aligo/vte,jessevdk/vte,pjm0616/vte,aligo/vte,rvu95/vte,rvu95/vte,jessevdk/vte,rvu95/vte,jessevdk/vte,gloob/vte-copy,saitoha/vte-sixel,saitoha/vte-sixel,asivokon/vte-fx,rvu95/vte,flaxandteal/gasket-vte,flaxandteal/gasket-vte,thestinger/vte-ng,thestinger/vte-ng,pjm0616/vte,aligo/vte,asivokon/vte-fx,thestinger/vte-ng