Don't be fooled by trailing '/' in url-parameter

cgit_parse_url() didn't check if the path-part of urls contained a
real path or just a trailing slash. This made the log-page die since
the path filtering supplied an invalid path argument. This fixes it.

Signed-off-by: Lars Hjemli <hjemli@gmail.com>

parsing.c

@@ -167,7 +167,8 @@ void cgit_parse_url(const char *url)
 		p = strchr(cmd + 1, '/');
 		if (p) {
 			p[0] = '\0';
-			cgit_query_path = xstrdup(p + 1);
+			if (p[1])
+				cgit_query_path = xstrdup(p + 1);
 		}
 		cgit_cmd = cgit_get_cmd_index(cmd + 1);
 		cgit_query_page = xstrdup(cmd + 1);