accept libmagic starting from 5.03
Sorry, that libmagic version actually might have some problems - at
least on the linux distribution I have access to. So... it was a
bad idea.

Revert "accept libmagic starting from 5.03"

This reverts commit 04dd363279283c56d205f0979aaa09aa70409391.
Dangling pointer fix.  Addresses #1004.
Merge remote-tracking branch 'origin/fastpath'

Closes #1004. Great job tracking this down!

* origin/fastpath:
  Dangling pointer fix.  Addresses #1004.
  Sorry, that libmagic version actually might have some problems - at least on the linux distribution I have access to. So... it was a bad idea.
  accept libmagic starting from 5.03