update flutter_volume

pubspec.yaml

@@ -18,7 +18,7 @@ dependencies:
       url: https://github.com/hwh97/flutter_screen.git
   sys_volume:
     git:
-      url: https://github.com/hwh97/flutter_volume.git
+      url: https://git.i2edu.net/plugins/flutter_volume.git
 #  event_bus:
 #    git:
 #      url: https://git.i2edu.net/plugins/event_bus.git