RoxenPatch: Fix pike version deps on WIN32.

For some reason the installation location of the version.h header file
for Pike differs on WIN32. We now check that location if there's no
file at the primary location.

Fixes [bug 7101].
Merge branch 'grubba/patchsystem' into 5.4

* grubba/patchsystem:
  RoxenPatch: Fix pike version deps on WIN32.