Fix reported test-tidy errors for unmerged import blocks

This merges import blocks that were reported by tidy as unmerged.

components/servo/main.rs

@@ -33,10 +33,9 @@ use servo::Browser;
 use servo::compositing::windowing::WindowEvent;
 use servo::net_traits::hosts;
 use servo::util::opts;
-use std::rc::Rc;
-
 #[cfg(target_os = "android")]
 use std::borrow::ToOwned;
+use std::rc::Rc;
 
 fn main() {
     env_logger::init().unwrap();