Remove ambiguity for RHEL8 python

RHEL8 doesn't want 'python', so python2 for now.

create_man_pages.py

@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/python2
 #TODO: Delete the old files to support removing a man page
 
 import glob

xCAT-probe/scripts/dbstats.py

@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/python2
 # -*- encoding: utf-8 -*-
 from __future__ import print_function
 import argparse

xCAT-server/xCAT-wsapi/xcatws-test.py

@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/python2
 """Usage:
   xcatws_test.py [--xcatmn=<xcatmn>] [--user=<user>] [--password=<password>]
 """