DOC-8751 -- Remove constraint (num_replications_active) (#526)

https://issues.couchbase.com/browse/DOC-8751

Author: ibsoln

modules/ROOT/pages/_partials/stats-schema-descriptions.adoc

@@ -538,8 +538,8 @@ The total number of documents written by any means (replication, rest API intera
 ==== num_replications_active
 Description::
 The total number of active replications.
-Constraints::
-This metric only counts continuous pull replications.
+This metric tracks all 2.0/BLIP-based connections, regardless of direction or type.
+It also tracks 1.x pull replications of any type.
 
 ==== num_replications_total
 Description::