python3: Strutils is not needed

strutils is used to safely encode and decode unicode strings
for python2.7. Since unicode strings are the default in python3,
ignore the use of strutils when running with python3.

Change-Id: I9a8e296b4f2153b1ef4302a7dcd797fbb4561c35
Signed-off-by: Chuck Short <chuck.short@canonical.com>
Merge "python3: Strutils is not needed"