Cloned from https://bugzilla.redhat.com/show_bug.cgi?id=1202564
Description of problem:
GET /api/v2/config_templates/build_pxe_default returns a message that has a content-type of application/json but is not JSON.

Version-Release number of selected component (if applicable):
Tested against Satellite-6.1.0-RHEL-6-20150311.1 and Satellite-6.1.0-RHEL-7-20150311.1.

How reproducible:
Always.

Steps to Reproduce:
1. GET /api/v2/config_templates/build_pxe_default
2. Examine the response payload.

Actual results:
'PXE Default file has been deployed to all Smart Proxies'

Expected results:
The payload is valid JSON. For example, something like this:

{
        'status': 'success',
        'message': 'PXE Default file has been deployed to all Smart Proxies',
    }

Additional info: