don't call (main) twice when running uncompiled

this set of patches gets repo2html working for me running as cli, both compiled
and not, for fa! there was one markdown file in fa that lowdown throws an error
about, i haven't investigated further. but i catch the error and render as
plaintext instead.

i haven't re-tested running as githook for pushing to fa and other repos yet.

main.scm

@@ -1,4 +1,4 @@
-#!/usr/bin/csi -ss
+#!/usr/bin/csi -s
 
 (import utf8
         lowdown