Fix link to the AQL spec page

Author: Bostjan Lah

src/includes/query_overview.apib

@@ -6,7 +6,7 @@ Release: **_Release_**
 
 This specification describes the service endpoints and data-models used when querying an openEHR system. 
 
-AQL [Archetype Query Language](#http://www.openehr.org/releases/QUERY/latest/docs/AQL/AQL.html) is the primary query language. 
+AQL [Archetype Query Language](https://www.openehr.org/releases/QUERY/latest/docs/AQL/AQL.html) is the primary query language. 
 
 The query `response` may also be used by other API endpoints in the openEHR REST API. 
 I.e. composition resource might return several compositions. These operations will return the `response`