fix empty message view showing/hiding at the wrong times

app/src/main/java/com/keylesspalace/tusky/fragment/TimelineFragment.java

@@ -300,6 +300,9 @@ public class TimelineFragment extends SFragment implements
                 break;
             }
         }
+        if(statuses.size() == 0) {
+            nothingMessageView.setVisibility(View.VISIBLE);
+        }
     }
 
     @Override
@@ -820,6 +823,8 @@ public class TimelineFragment extends SFragment implements
         swipeRefreshLayout.setRefreshing(false);
         if (this.statuses.size() == 0) {
             nothingMessageView.setVisibility(View.VISIBLE);
+        } else {
+            nothingMessageView.setVisibility(View.GONE);
         }
     }