LiveList: fix setState after dispose (#475)

Author: fischerscode

packages/flutter/lib/src/utils/parse_live_list.dart

@@ -134,6 +134,13 @@ class _ParseLiveListWidgetState<T extends sdk.ParseObject>
         : buildAnimatedList();
   }
 
+  @override
+  void setState(VoidCallback fn) {
+    if (mounted) {
+      super.setState(fn);
+    }
+  }
+
   Widget buildAnimatedList() {
     return AnimatedList(
         key: _animatedListKey,
@@ -235,6 +242,13 @@ class _ParseLiveListElementWidgetState<T extends sdk.ParseObject>
 
   StreamSubscription<T> _streamSubscription;
 
+  @override
+  void setState(VoidCallback fn) {
+    if (mounted) {
+      super.setState(fn);
+    }
+  }
+
   @override
   void dispose() {
     _streamSubscription?.cancel();