fixes the 7zip call in the itunes install which is not playing nice with...

I tried installing itunes yesterday with this package and it failed because 7zip did not expand the downloaded .EXE. For some reason, not sure why, using Start-Process fails. My guess is that this likely failed from a recent change in the 7zip command line tools. The install for Chocolatey experienced a similar issue a few weeks ago. At any rate, it looks like using Start-process here is unnecessary. The call to 7za is synchronous and testing this on a clean OS VM, it succeeds if I remove the Start-Process command and call 7za directly.