job/queue: add move assignment operator for cookie

job/queue.hpp

@@ -81,7 +81,11 @@ namespace util::job {
                 std::swap (data, rhs.data);
             }
 
-            cookie& operator= (cookie&&) = delete;
+            cookie& operator= (cookie &&rhs)
+            {
+                std::swap (data, rhs.data);
+                return *this;
+            }
 
             cookie (const cookie&) = delete;
             cookie& operator= (const cookie&) = delete;