Updated link to for browsing to financial years

The link which when clicked allows the user to view different financial
years was pointing to the template_activity page. Updated to the link
to point to the new page.

app/main/views/dashboard.py

@@ -142,7 +142,7 @@ def template_usage(service_id):
             for month in months
         ),
         years=get_tuples_of_financial_years(
-            partial(url_for, '.template_history', service_id=service_id),
+            partial(url_for, '.template_usage', service_id=service_id),
             end=current_financial_year,
         ),
         selected_year=year