Bump zuul version - 2.1.1-19.gdc
Bump zuul version - 2.1.1-19.gdc

Sync with upstream, supersedes a partial cherry-pick 7cf9ebd.
Revert backward compatibility changes.

Change-Id: I0afc0b1eb16891a6e0f0fca43c6fe02f029ef691

gooddata/zuul,gooddata/zuul,gooddata/zuul,gooddata/zuul,gooddata/zuul