chore: Fix formatting of 6.19.0 and 6.19.1 changelog entries (#4763)
chore: Fix formatting of 6.19.0 and 6.19.1 changelog entries (#4763)

Add `-` to make sure the CHANGELOG entry items render as a list
getsentry/raven-js,getsentry/raven-js,getsentry/raven-js,getsentry/raven-js