rearranged the orders of the help text

src/main.c

@@ -272,10 +272,11 @@ static void print_http_options()
                             size.\n\
         --max-conns         The maximum number of network connections that\n\
                             libcurl is allowed to make, default to 10.\n\
-        --user-agent        The user agent string, default to \"HTTPDirFS\".\n\
         --retry-wait        The waiting interval in seconds before making an\n\
                             HTTP request, after encountering an error, \n\
                             default to 5 seconds.\n\
+        --user-agent        The user agent string, default to \"HTTPDirFS\".\n\
+\
     \n\
 libfuse options:\n");
 }