Issue  6058: Make nicknames in reviewer and cc fields case sensitive.
Issue  6058: Make nicknames in reviewer and cc fields case sensitive.

nicko96/Chrome-Infra,nicko96/Chrome-Infra,nicko96/Chrome-Infra,riannucci/rietveldv2,nicko96/Chrome-Infra,riannucci/rietveldv2,nicko96/Chrome-Infra