Corrects outdated guidance on shared services bindings
Corrects outdated guidance on shared services bindings

* This fixes the documentation around determining whether a service
binding is being requested for an app in the originating space of the
service instance or for an app whose space has access to the service
instance via a share.

[#155945946]

Signed-off-by: Luis Urraca <bf7425dc8820b4c374aec067efaf28f949addc6b@pivotal.io>

cloudfoundry/docs-services