Fix create_security_group_rule to work with python 2.6

Change 59f00281ef1fa9448f5caf78a1c558625c83f65e introduced new code
which only works on python 2.7. This patch keeps the same function as
that change but makes it also work on python 2.6.

Fixes bug 1193066

Change-Id: I701259020f1ff15c0082328895ddc32cec9d3da1
1 file changed