s4-waf: don't generate PACKAGE_* defines in config.h

s4-waf: don't generate PACKAGE_* defines in config.h

- We don't use them anywhere (heimdal has special rules)
- They calculate the version at configure time
  and may contain the wrong git hash while building
- If we really need them in future we should add them
  to version.h and not config.h, as the changing git hash
  will trigger a full rebuild if config.h changes.

metze