Small improvements

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

@@ -180,11 +180,11 @@ public class FragmentMessage extends FragmentEx {
 
     @Override
     public void onDestroy() {
-        super.onDestroy();
         if (openPgpConnection != null) {
             openPgpConnection.unbindFromService();
             openPgpConnection = null;
         }
+        super.onDestroy();
     }
 
     @Override
@@ -389,6 +389,12 @@ public class FragmentMessage extends FragmentEx {
         return view;
     }
 
+    @Override
+    public void onDestroyView() {
+        adapter = null;
+        super.onDestroyView();
+    }
+
     @Override
     public void onSaveInstanceState(Bundle outState) {
         super.onSaveInstanceState(outState);