Add Pavel Novitskiy to the CHANGELOG

CHANGELOG

@@ -10,6 +10,7 @@ v 7.3.0
   - Support Unix domain sockets for Redis
   - Store session Redis keys in 'session:gitlab:' namespace
   - Deprecate LDAP account takeover based on partial LDAP email / GitLab username match
+  - Use /bin/sh instead of Bash in bin/web, bin/background_jobs (Pavel Novitskiy)
   - Keyboard shortcuts for productivity (Robert Schilling)
   - API: filter issues by state (Julien Bianchi)
   - API: filter issues by labels (Julien Bianchi)