Use GIT-1.7.3

This fixes http://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2010-2542.

Noticed-by: Silvio Cesare <silvio.cesare@gmail.com>
Signed-off-by: Lars Hjemli <hjemli@gmail.com>

cgit.c

@@ -21,7 +21,7 @@ void add_mimetype(const char *name, const char *value)
 {
 	struct string_list_item *item;
 
-	item = string_list_insert(xstrdup(name), &ctx.cfg.mimetypes);
+	item = string_list_insert(&ctx.cfg.mimetypes, xstrdup(name));
 	item->util = xstrdup(value);
 }