Ruby 2.0 compatibility fix
Issue #117: Fixed wrong magic comparition.

Signed-off-by: Mikhail S. Pobolovets <styx.mp@gmail.com>
Removed not used constant.

Signed-off-by: Mikhail S. Pobolovets <styx.mp@gmail.com>
Merge branch 'Issue_117'
Merge branch 'master' of github.com:styx/grit