Try multiple versions of autoconf, too.
Try multiple versions of autoconf, too.

	* autogen.sh: Try multiple versions of autoconf, too.

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