MB-5734: Fix _random doc feature
MB-5734: Fix _random doc feature

Change-Id: I512817e156252005f484cd29e9fba2bb8d6f1b40
[76658a2722cfc360b68a81107f0c193549bc08f4@tut.by: rebased and added reference to ticket]
Signed-off-by: Aliaksey Kandratsenka <76658a2722cfc360b68a81107f0c193549bc08f4@tut.by>
Reviewed-on: http://review.couchbase.org/17781
Reviewed-by: Aliaksey Kandratsenka <340b8e09ca65cd3fc686427fcfed17e87eaf61e2@gmail.com>
Tested-by: Aliaksey Kandratsenka <340b8e09ca65cd3fc686427fcfed17e87eaf61e2@gmail.com>

membase/ns_server,daverigby/ns_server,vzasade/ns_server,nimishzynga/ns_server,mschoch/ns_server,t3rm1n4l/ns_server,mschoch/ns_server,membase/ns_server,pavel-blagodov/ns_server,pavel-blagodov/ns_server,daverigby/ns_server,nimishzynga/ns_server,t3rm1n4l/ns_server,ceejatec/ns_server,daverigby/ns_server,ceejatec/ns_server,daverigby/ns_server,pavel-blagodov/ns_server,vzasade/ns_server,membase/ns_server,mschoch/ns_server,nimishzynga/ns_server,t3rm1n4l/ns_server,mschoch/ns_server,nimishzynga/ns_server,t3rm1n4l/ns_server,nimishzynga/ns_server,ceejatec/ns_server,ceejatec/ns_server,pavel-blagodov/ns_server,mschoch/ns_server,vzasade/ns_server,membase/ns_server,vzasade/ns_server,membase/ns_server,membase/ns_server,daverigby/ns_server,nimishzynga/ns_server,ceejatec/ns_server,mschoch/ns_server,ceejatec/ns_server,t3rm1n4l/ns_server