Revert "Do no use python_provide conditionally"
The macro python_provide is defined in /usr/lib/rpm/macros.d/macros.python
in the package python-rpm-macros. But this package is not part
of build root and therefore rpm cannot parse spec file.
This reverts commit 22c180263aad50325d9e6c8a946fc8b6386fc694.
(cherry picked from commit 8dd054482d1a06ccb0125740b70b483e5e0fcf5e)
(cherry picked from commit a8ed2fc10792b5416d7966bee118b4859f36b608)