Stats: only take finished sessions into account

app/src/main/java/net/pokeranalytics/android/ui/fragment/components/SessionObserverFragment.kt

@@ -10,14 +10,14 @@ open class SessionObserverFragment : PokerAnalyticsFragment() {
 
     init {
         val realm = Realm.getDefaultInstance()
-        this.sessions = realm.where(Session::class.java).findAll()
+        this.sessions = realm.where(Session::class.java).isNotNull("timeFrame.endDate").findAll()
         this.sessions.addChangeListener { _, _ ->
             this.sessionsChanged()
         }
     }
 
     open fun sessionsChanged() {
-
+        // to override
     }
 
 }