Update contact address in code of conduct

The code of conduct contains for Ekaterina, who is no longer at Collabora.
Update the page to contain the new "conduct@apertis.org" email alias which
has been setup for this purpose.

Signed-off-by: Martyn Welch <martyn.welch@collabora.com>

content/policies/code_of_conduct.md

@@ -42,9 +42,8 @@ community communication channels and at all events.
 
 ## Who can I approach?
 
-You can approach the following people for help:
-
-  - Ekaterina Gerasimova \<ekaterina.gerasimova@collabora.co.uk\>
+Senior representatives of the Apertis project can be contacted via
+email at [conduct@apertis.org](mailto:conduct@apertis.org)
 
 ## Credits