fix conductor backstack when chat notification is opened

when opening a chat notification, the old chat should not be kept in the backstack. so when clicking the back button when coming from a chat that was opened by a notification, now the ConversationList opens.

by the way, this also avoids to run into bug #2181 (but it's root cause is not solved yet)

Signed-off-by: Marcel Hibbe <dev@mhibbe.de>

app/src/main/java/com/nextcloud/talk/activities/MainActivity.kt

@@ -354,7 +354,7 @@ class MainActivity : BaseActivity(), ActionBarProvider {
                     intent.getParcelableExtra<User>(KEY_USER_ENTITY)!!.id!!,
                     intent.getStringExtra(KEY_ROOM_TOKEN)!!,
                     intent.extras!!,
-                    false,
+                    true,
                     true
                 )
                 logRouterBackStack(router!!)