libev handler is now copyable

Author: EmielBruijntjes

include/dnscpp/libev.h

@@ -83,12 +83,6 @@ class LibEv : public Loop
      */
     LibEv(struct ev_loop *loop, bool persist = true) : _loop(loop), _persist(persist) {}
 
-    /**
-     *  No copying
-     *  @param  that
-     */
-    LibEv(const LibEv &that) = delete;
-    
     /**
      *  Destructor
      */