configure: Python tests must be done before help message The help message uses $python and displays its value, so that macro should be tested and set early. With this modification, configure --help displays the correct value (usually python -B) and no longer creates several *.pyc files. Signed-off-by: Stefan Weil <sw@weilnetz.de> Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>