Here's the link https://aur.archlinux.org/packages.php?ID=49992 I reuploaded under the name mkvmerge-gui because the name fits better (I also added mmg and mkvtoolnix to the description, so it can be found as good as possible)
And here's the link to mkvtoolnix-nogui https://aur.archlinux.org/packages.php?ID=41546 This isn't needed anymore, because repo's mkvtoolnix removed the mkvmerge-gui mmg. A package called eunektes requires this version, but I informed the maintainer in the comment section to adjust the dependency. Merci beaucoup
