tests: Skip Python tests if the bindings are not built.
* tests/gpgme/wrap.scm (python): Move variable... * tests/gpgme/gpgme-defs.scm (python): ... here. (run-python-tests?): New function. * tests/gpgme/run-tests.scm: Only run Python tests if the bindings can be located in GPGME's build directory.
- Signed-off-by: Justus Winter <justus@g10code.com>