[Hawtio + RHSSO] Not able to load keycloak.js for Fuse on EAP 7.5

I found out about this issue thanks to FUSEDOC-3061.
Tested with:

• fuse-eap 7.5.0 GA
• RHSSO 7.3.5
• EAP 7.2.5

I was only checking the integration of Hawtio on Fuse 7.5 on eap and RHSSO. After the configuration, the login page of Hawtio should be redirected to RHSSO login page. But the page is blank in Chrome and in Firefox we can see this message:

[Keycloak] Not able to load keycloak.js from: undefined/js/keycloak.js

In Firefox console, there is this error:

The resource from “http://localhost:8181/hawtio/undefined/js/keycloak.js” was blocked due to MIME type (“text/html”) mismatch (X-Content-Type-Options: nosniff).

Weird thing is, that this error is there only if I use the fuse eap installer from here:
http://download.eng.brq.redhat.com/released/JBoss-middleware/fuse/7.5.0/
When I use the one from our nexus (this vesion is GA), everything is OK and integration works:
http://nexus.fuse-qe.eng.rdu2.redhat.com/repository/fuse-all/com/redhat/fuse/eap/fuse-eap-installer/7.5.0.fuse-750024-redhat-00002/fuse-eap-installer-7.5.0.fuse-750024-redhat-00002.jar
That's why I didn't encounter the issue while testing 7.5. The version with which I was testing is functional. But I can't explain why. Both jars are the same, they have same checksums and diff didn't return any difference. I used the same steps in configuration.

This integration for 7.6 was tested correctly.