Check result for undefined and prevent JSON Parse

[bpeters]

I was running into issues where getState script would result in undefined which would cause the JSON.parse(result) to throw and error.

[andrehaveman]

I don't see the use of this change. The JSON.parse error is already handled by try/catch block. This change leads to the undesired result that the callback is called without an error and also without a result.

[Alutun]

@bpeters Di you find the cause of it ? i'm running into the same issue and cannot find the root cause of this.

[will234]

nn

[nzec]

@bpeters I don't think this fixes the problem.