Add type hint to Thread/sleep in do-every macro

Caused by recent versions of Java allowing Thread/sleep to be called
with a Duration instance. Fixes #498.

ring-core/src/ring/middleware/multipart_params/temp_file.clj

@@ -11,7 +11,7 @@
 (defmacro ^{:private true} do-every [delay & body]
  `(background-thread
  #(while true
- (Thread/sleep (* ~delay 1000))
+ (Thread/sleep ~(with-meta `(* ~delay 1000) {:tag 'long}))
  (try ~@body
  (catch Exception ex#)))))