Add GPL-2.0-or-later license header found in okular
The conversion of https://invent.kde.org/graphics/okular/-/blob/master/core/synctex/synctex_parser_utils.c#L34 is unclear to me.
cc @aacid
The conversion of https://invent.kde.org/graphics/okular/-/blob/master/core/synctex/synctex_parser_utils.c#L34 is unclear to me.
cc @aacid