## Bug description
I added an event (that exists) to an action, and now my action hangs forever.

I added an insight viewed event

w/ filters `insight == RETENTION` and `same_retention_and_cohortizing_event = false` – this appears to have broken my action where it does not load and I cannot edit it.

Cannot reproduce this same behavior locally.


## Expected behavior
- The action loads if the schema is correct.
-  If there's erroneous data it should load and let me edit it.

## How to reproduce

1. Create an action on Posthog cloud, in our main app
2. Add 'insight viewed' with filters `insight == RETENTION` and `same_retention_and_cohortizing_event = false`
3. The action will spin forever

## Environment

- [x] PostHog Cloud
- [ ] self-hosted PostHog, version/commit: _please provide_

## Additional context

[Sentry error](https://sentry.io/organizations/posthog/issues/2378948964/?project=1899813&referrer=slack)

Console errors 
<img width="1607" alt="Screen Shot 2021-05-03 at 5 45 39 PM" src="https://user-images.githubusercontent.com/5965891/116950024-b0d7a280-ac38-11eb-93c8-245390240532.png">
<img width="1167" alt="Screen Shot 2021-05-03 at 5 51 34 PM" src="https://user-images.githubusercontent.com/5965891/116950026-b208cf80-ac38-11eb-96e1-6a8f018f650a.png">



#### *Thank you* for your bug report – we love squashing them!

ee/clickhouse/models/property.py
if len(attributes.keys()) > 0:
        or_conditions = []
        for key, value_list in attributes.items():
            for idx, value in enumerate(value_list):
                params["{}_{}_{}_attributes_regex".format(prepend, key, idx)] = ".*?({}).*?".format(
                    ".*?".join(['{}="{}"'.format(key, value)])
                )
                or_conditions.append("match(elements_chain, %({}_{}_{}_attributes_regex)s)".format(prepend, key, idx))
            if len(or_conditions) > 0:
                conditions.append("(" + (" OR ".join(or_conditions)) + ")")
    return (conditions, params)
def _create_regex(selector: Selector) -> str:
    regex = r""
    for idx, tag in enumerate(selector.parts):
        if tag.data.get("tag_name") and isinstance(tag.data["tag_name"], str):
            if tag.data["tag_name"] == "*":
                regex += ".+"
            else:
                regex += tag.data["tag_name"]
        if tag.data.get("attr_class__contains"):
            regex += r".*?\.{}".format(r"\..*?".join(sorted(tag.data["attr_class__contains"])))
        if tag.ch_attributes:
            regex += ".*?"
            for key, value in sorted(tag.ch_attributes.items()):
                regex += '{}="{}".*?'.format(key, value)
        regex += r"([-_a-zA-Z0-9\.]*?)?($|;|:([^;^\s]*(;|$|\s)))"
        if tag.direct_descendant:
            regex += ".*"
    return regex