fix memory leak in gtk

[linphone] / mediastreamer2

diff --git a/mediastreamer2 b/mediastreamer2
index 4f93003c1eade1442fdedd8dee10f18c98ec47c3..25b0496dbc62183f195528481fe44c73e0d201e9 160000 (submodule)
--- a/mediastreamer2
+++ b/mediastreamer2
@@ -1 +1 @@
-Subproject commit 4f93003c1eade1442fdedd8dee10f18c98ec47c3
+Subproject commit 25b0496dbc62183f195528481fe44c73e0d201e9