Remove unused code.

src/uxbox/main/state/clipboard.cljs

@@ -1,16 +0,0 @@
-(ns uxbox.main.state.clipboard)
-
-(defonce ^:private +max-items+ 5)
-
-(defn conj-item
-  [state item]
-  (if-let [project (get-in state [:workspace :project])]
-    (let [queue (get-in state [:clipboard project] #queue [])
-          queue (conj queue item)]
-      (assoc-in state [:clipboard project]
-                (if (> (count queue) +max-items+)
-                  (pop queue)
-                  queue)))
-    (do
-      (js/console.warn "no active project for manage clipboard.")
-      state)))