relax clone trait bound on context

Signed-off-by: Petros Angelatos <[email protected]>

src/producer/base_producer.rs

@@ -639,7 +639,6 @@ where
 /// queued events, such as delivery notifications. The thread will be
 /// automatically stopped when the producer is dropped.
 #[must_use = "The threaded producer will stop immediately if unused"]
-#[derive(Clone)]
 pub struct ThreadedProducer<C, Part: Partitioner = NoCustomPartitioner>
 where
     C: ProducerContext<Part> + 'static,
@@ -772,6 +771,16 @@ where
     }
 }
 
+impl<C: ProducerContext + 'static> Clone for ThreadedProducer<C> {
+    fn clone(&self) -> Self {
+        Self {
+            producer: Arc::clone(&self.producer),
+            should_stop: Arc::clone(&self.should_stop),
+            handle: self.handle.clone(),
+        }
+    }
+}
+
 impl<C, Part> Drop for ThreadedProducer<C, Part>
 where
     Part: Partitioner,