Bug#924321: python-openflow: please stop buildd-depending on py3.6

now NMUed. This was the last package preventing the removal of python3.6 in unstable.

Bug#924321: python-openflow: please stop buildd-depending on py3.6

Source: python-openflow Version: Severity: serious Control: block 924018 by -1 Dear maintainer, your package block the removal python 3.6. Please stop build-depending on it, and in general please always prefer to build-depend only on the unversioned python variants (which you already do,