MULE-7686: Upgrade Jetty version to 9
MULE-7686: Upgrade Jetty version to 9

Fixed whitelist, added references to improvement issues and removed Jetty connector class property.
Merge pull request #804 from mulesoft/MULE-7686

MULE-7686: Upgrade Jetty version to 9
Merge remote-tracking branch 'origin/mule-4.x' into mule-4.x