update conduct email group (#41)

motivation: use consistent email across swift server projects

changes: set conduct email address to [email protected]

Author: tomerd

CODE_OF_CONDUCT.md

@@ -49,7 +49,7 @@ of an incident.
 *This policy is adapted from the Contributor Code of Conduct [version 1.3.0](https://contributor-covenant.org/version/1/3/0/).*
 
 ### Reporting
-A working group of community members is committed to promptly addressing any [reported issues](mailto:swift-metrics[email protected]).
+A working group of community members is committed to promptly addressing any [reported issues](mailto:swift-server[email protected]).
 Working group members are volunteers appointed by the project lead, with a
 preference for individuals with varied backgrounds and perspectives. Membership is expected
 to change regularly, and may grow or shrink.