Rename gmail for previous events

[asendecka]

We recently fixed renaming email if there is completely new team organizing the event. However, it changes e-mail on Event only for previous event. If the same team organized first two editions of DG in the same city and then different team is organizing third one, second event will have email changed, but first one will not.

[amakarudze]

@marksweb And this one too? Just asking so I know whether to close some of these issues.

[marksweb]

Yeah this is unrelated as well @amakarudze