Clarify the target of the events redesign discussion at ESC

Following the conversation [1] on the mailing list, add an extra
clarification on which version will be targeted by Luca and his
GerritForge team for the event system evolution in Gerrit.

Also remove redundant indenting on the corresponding paragraph.

[1] https://groups.google.com/g/repo-discuss/c/027jSo80M30

Change-Id: Icea98dca793b567ff4019b3e892b1adefb99a7f6
1 file changed