[in_app_purchase]fix version (#3022)

diff --git a/packages/in_app_purchase/pubspec.yaml b/packages/in_app_purchase/pubspec.yaml
index e831d90..52abe96 100644
--- a/packages/in_app_purchase/pubspec.yaml
+++ b/packages/in_app_purchase/pubspec.yaml
@@ -1,7 +1,7 @@
 name: in_app_purchase
 description: A Flutter plugin for in-app purchases. Exposes APIs for making in-app purchases through the App Store and Google Play.
 homepage: https://github.com/flutter/plugins/tree/master/packages/in_app_purchase
-version: 0.3.4+7
+version: 0.3.4+8
 
 dependencies:
   async: ^2.0.8