component/6tunnel: simplify pre-configure

This does not seem to use autoheader and automake, these commands exists
with error code and don't touch any local files when executed, so don't
run them, because since slapos.recipe.cmmi 0.13, we check exit code of
each command in multi line commands

component/6tunnel/buildout.cfg

@@ -10,12 +10,10 @@ extends =
 [6tunnel]
 recipe = slapos.recipe.cmmi
 shared = true
-url = http://toxygen.net/6tunnel/6tunnel-0.11rc2.tar.gz
+url = https://github.com/wojtekka/6tunnel/releases/download/0.11rc2/6tunnel-0.11rc2.tar.gz
 md5sum = 74e02d4f0704b3083a01feda66033449
 pre-configure =
   aclocal
-  autoheader
-  automake --foreign
   autoconf
 environment =
   PATH=${autoconf:location}/bin:${automake:location}/bin:%(PATH)s