Added operations subtitle

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

@@ -45,6 +45,8 @@ public class FragmentOperations extends FragmentEx {
     @Override
     @Nullable
     public View onCreateView(@NonNull LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
+        setSubtitle(R.string.menu_operations);
+
         View view = inflater.inflate(R.layout.fragment_operations, container, false);
 
         // Get controls