Need to set VTE_API_VERSION
Need to set VTE_API_VERSION

Configure needs to properly set VTE_API_VERSION to use the same library
names as previous gtk3-based vte releases, and to prevent file collisions
with gtk2-based vte.

https://bugzilla.gnome.org/show_bug.cgi?id=657584

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