Merge branch 'security-10-3-do-not-expose-passwords-or-tokens-in-service-integrations-api' into 'security-10-3'

Filter out sensitive fields from the project services API

See merge request gitlab/gitlabhq!2281

(cherry picked from commit 476f2576444632f2a9a61b4cead9c1077f2c81d7)

2bcbbda0 Filter out sensitive fields from the project services API