Pages do not load on test environments after upgrade to 3.40

Problem/Motivation

After upgrading to 3.40 Instapages created on our test environment no longer work even though Instapages are specifically created for that domain. Resulting in the error:
{"status":"ERROR","message":"Request failed. Client error: `POST http:\/\/plugin.pageserve.co\/landing\/the-page-url-here` resulted in a `404 Not Found` response:\n\n\n\n\t\n\t\n\t\t\t\t\t\t\t\t\t\t\t\n\t\t\t\t

Steps to reproduce

1. Upgrade to 3.40
2. test any page created with the instapage module on a domain other than your production domain
3. Receive error message

,

Proposed resolution

In the 3.40 release the host is no longer being explicitly set. Revert that change