fix(migrations): Skip over problematic events for Snuba migrat… (#16770)
fix(migrations): Skip over problematic events for Snuba migrat… (#16770)

Adds a workaround for https://github.com/getsentry/onpremise/issues/366#issuecomment-581074102. Also fixes

```
RuntimeWarning: DateTimeField Event.datetime received a naive datetime (2020-02-01 19:06:53.816964) while time zone support is active.  RuntimeWarning)
```

beeftornado/sentry,beeftornado/sentry,beeftornado/sentry