Prevent crash

app/src/main/java/eu/faircode/email/FragmentMessages.java

@@ -449,12 +449,16 @@ public class FragmentMessages extends FragmentEx {
                 public void onSelectionChanged() {
                     // Workaround AndroidX bug
                     FragmentActivity activity = getActivity();
-                    if (activity != null) {
+                    if (activity != null)
+                        try {
                             ViewModelMessages modelMessages = ViewModelProviders.of(activity).get(ViewModelMessages.class);
                             if (selectionTracker.hasSelection())
                                 modelMessages.removeObservers(viewType, getViewLifecycleOwner());
                             else
                                 modelMessages.observe(viewType, getViewLifecycleOwner(), observer);
+                        } catch (IllegalStateException ex) {
+                            // getViewLifecycleOwner
+                            Log.w(ex);
                         }
 
                     if (selectionTracker.hasSelection()) {