MB-8688: Readjust python path for new tools

Change-Id: I7303823ac2876b42a4f2140d7b57ae570d92c8fe
Reviewed-on: http://review.couchbase.org/28004
Reviewed-by: Pavel Paulau <pavel.paulau@gmail.com>
Tested-by: Bin Cui <bin.cui@gmail.com>