[DOCS] Adds link to clear role cache API (elastic/x-pack-elasticsearch#4405)
[DOCS] Adds link to clear role cache API (elastic/x-pack-elasticsearch#4405)

Original commit: elastic/x-pack-elasticsearch@a79714510bd4dfee2ea979109e1dc2787560db7a

strapdata/elassandra,vroyer/elassandra,vroyer/elassandra,strapdata/elassandra,strapdata/elassandra,vroyer/elassandra,strapdata/elassandra,strapdata/elassandra