Update old links in common_errors.html

Due to the website and publisher guidance moving, some links were out of date. One gave a 404 error and the other had a redirect but should link to the correct place.

Author: mariongalley

cove/cove_360/templates/cove_360/common_errors.html

@@ -20,7 +20,7 @@ <h3>{% trans "Invalid 'uri' found" %}</h3>
 
   <a id="date-time" class="anchor"></a>
   <h3>{% trans "Date is not in the correct format" %}</h3>
-  <p>{% blocktrans %}Dates should be in the formats defined by the <a href="https://www.threesixtygiving.org/standard/reference/">360Giving Data Standard</a>.{% endblocktrans %}</p>
+  <p>{% blocktrans %}Dates should be in the formats defined by the <a href="https://www.360giving.org/about/data-standard/">360Giving Data Standard</a>.{% endblocktrans %}</p>
   <p>{% blocktrans %}All Last Modified fields should be in datetime format and all other dates, such as Award Dates and Planned Dates, should be in the YYYY-MM-DD format. However, Award and Planned Dates can also be provided in datetime format.{% endblocktrans %}</p>
 
   <h4>{% blocktrans %}YYYY-MM-DD format used for full dates{% endblocktrans %}</h4>
@@ -152,7 +152,7 @@ <h3>{% trans "<code>x</code> is less than the minimum of 0" %}</h3>
 
 
   <h2>{% trans "Getting further help" %}</h2>
-    <p>{% blocktrans %}For further information see our guide on using the <a href="https://standard.threesixtygiving.org/en/latest/guidance/data-quality/">data quality tool</a> and <a href="https://standard.threesixtygiving.org/en/latest/technical/reference/">technical reference</a> for the 360Giving Data Standard.{% endblocktrans %}</p>
+    <p>{% blocktrans %}For further information see our guide on using the <a href="https://www.360giving.org/publish/guidance/prepare/check-data-quality/">data quality tool</a> and <a href="https://standard.threesixtygiving.org/en/latest/technical/reference/">technical reference</a> for the 360Giving Data Standard.{% endblocktrans %}</p>
 
 
     <p>&nbsp;</p>