Fix issues for real this time :)

Signed-off-by: Mario Danic <mario@lovelyhq.com>

app/src/main/java/com/nextcloud/talk/presenters/MentionAutocompletePresenter.java

@@ -79,7 +79,7 @@ public class MentionAutocompletePresenter extends RecyclerViewPresenter<Mention>
 
     @Override
     protected RecyclerView.Adapter instantiateAdapter() {
-        adapter = new FlexibleAdapter<>(abstractFlexibleItemList, context, true);
+        adapter = new FlexibleAdapter<>(abstractFlexibleItemList, context, false);
         adapter.addListener(this);
         return adapter;
     }
@@ -115,6 +115,10 @@ public class MentionAutocompletePresenter extends RecyclerViewPresenter<Mention>
                                                     currentUser));
                                 }
 
+                                if (adapter.getItemCount() != 0) {
+                                    adapter.clear();
+                                }
+
                                 adapter.updateDataSet(internalAbstractFlexibleItemList);
                             }
                         }