iotests: Drop Python version from 065's Shebang

Test 065 specified python2 to be used in its Shebang; this might not
work on systems without a python2 symlink and furthermore it is now
counter-productive, as the check script compares the Shebang to
"#!/usr/bin/env python" and only uses the Python interpreter selected by
configure on an exact match.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
