Don't overwrite $crisp array when initializing.

[tikotzky]

What does this PR do? Currently there is no way to call crisp methods since when the integration loads it overwrites the $crisp array.

This PR update the integration to leave the $crisp array alone if its exists similar to how its done for google analytics (and others)

Are there breaking changes in this PR?

NO

Testing

I cant access the link provided, however I think Testing not required for this change.

Any background context you want to provide?

Is there parity with the server-side/android/iOS integration components (if applicable)? Not applicable

Does this require a new integration setting? If so, please explain how the new setting works No new setting required

Links to helpful docs and other external resources