Update Gerrit v3.6.0 link to rc4
Update Gerrit v3.6.0 link to rc4

Change-Id: I2198427849f2f34aa72e71765ea640a75a2740ec

GerritCodeReview/homepage,GerritCodeReview/homepage,GerritCodeReview/homepage,GerritCodeReview/homepage,GerritCodeReview/homepage