MB-100: fix requests incompatibility in active_tasks scripts

Change-Id: Ia9157701d0c3aca681f440df4d8d36b0c223c2eb
Reviewed-on: http://review.couchbase.org/24414
Reviewed-by: Pavel Paulau <pavel.paulau@gmail.com>
Tested-by: Pavel Paulau <pavel.paulau@gmail.com>