fix : property _unreadMessages set at 0

Change-Id: I7e4a5a9e745abedbb5c5584890e66bbbb7273e4c
Tuleap: #1203

SmartPanel.xaml.cpp

@@ -255,15 +255,22 @@ SmartPanel::_smartList__SelectionChanged(Platform::Object^ sender, Windows::UI::
     }
 
     auto call = item->_call;
+    auto contact = item->_contact;
+
     if (call) {
         auto state = call->state;
+
         if (state == CallStatus::IN_PROGRESS) {
+            if (contact) {
+                contact->_unreadMessages = 0;
+                ContactsViewModel::instance->saveContactsToFile();
+            }
+
             summonVideoPage();
             return;
         }
     }
 
-    auto contact = item->_contact;
     if (contact) {
         summonMessageTextPage();
         contact->_unreadMessages = 0;