Fix potential crash in WhitelistFragment

app/src/main/java/de/kuschku/quasseldroid/ui/clientsettings/whitelist/WhitelistFragment.kt

@@ -65,7 +65,7 @@ class WhitelistFragment : SettingsFragment(), SettingsFragment.Changeable,
 
   override fun onCreate(savedInstanceState: Bundle?) {
     super.onCreate(savedInstanceState)
-    handlerThread = HandlerThread("Crash")
+    handlerThread = HandlerThread("Whitelist")
     handlerThread.start()
     handler = Handler(handlerThread.looper)
   }
@@ -99,9 +99,11 @@ class WhitelistFragment : SettingsFragment(), SettingsFragment.Changeable,
         hostnameAdapter.list = it.hostnames
       }
 
+      activity?.runOnUiThread {
         certificateListEmpty.visibleIf(whitelist?.certificates.isNullOrEmpty())
         hostnameListEmpty.visibleIf(whitelist?.hostnames.isNullOrEmpty())
       }
+    }
     return view
   }