ui-shared: silence warning

warning: format ‘%ld’ expects type ‘long int’, but argument 2 has type
‘size_t’

Signed-off-by: Bernhard Reutner-Fischer <rep.dot.nop@gmail.com>
Signed-off-by: Lars Hjemli <hjemli@gmail.com>

ui-shared.c

@@ -466,7 +466,7 @@ void cgit_print_http_headers(struct cgit_context *ctx)
 	else if (ctx->page.mimetype)
 		htmlf("Content-Type: %s\n", ctx->page.mimetype);
 	if (ctx->page.size)
-		htmlf("Content-Length: %ld\n", ctx->page.size);
+		htmlf("Content-Length: %zd\n", ctx->page.size);
 	if (ctx->page.filename)
 		htmlf("Content-Disposition: inline; filename=\"%s\"\n",
 		      ctx->page.filename);