Packaging with Steam VR plugin disabled requires an IDE

Disabling the SteamVR plugin in a Blueprint-Only project causes the packaging process to require an IDE to complete, as it requires compilation.

Regression?: Yes
This did not occur in 4.16.2

Note: This only occurs in 4.17 and does not occur in 4.18 (Dev-Main)
The attached logs are from a computer that does have Visual Studio installed, to show what is being compiled.

Tested in the following branches:
4.16.2-3514769+++UE4+Release-4.16 (Did not occur)
4.17.0-3539194+++UE4+Release-4.17 (Did occur)
4.18.0-3532166+++UE4+Main (Did not occur)

1. Create a new blueprint-only project on a computer without Visual Studio installed
2. Disable the SteamVR plugin (restart as prompted)
3. Package the project (tested packaging for Windows 64-bit)
   Result: A message appears mentioning that Visual Studio 2015 must be installed.
   Expected: The project begins to package and completes successfully