Return the correct RDS Instance Endpoint in the ConnectionSecret

Previously the ConnectionSecret endpoint field contained the hostname
including the port.

This is not expected behaviour and makes the ConnectionSecret unuseable
by downstream consumers of the Secret, like
https://github.com/crossplane-contrib/provider-sql, which expected
the endpoint and port to be in seperate fields.

Fixes: crossplane-contrib#778

config/rds/config.go

@@ -108,12 +108,10 @@ func Configure(p *config.Provider) {
 		}
 		r.Sensitive.AdditionalConnectionDetailsFn = func(attr map[string]any) (map[string][]byte, error) {
 			conn := map[string][]byte{}
-			if a, ok := attr["endpoint"].(string); ok {
-				conn["endpoint"] = []byte(a)
-			}
 			if a, ok := attr["address"].(string); ok {
 				conn["address"] = []byte(a)
 				conn["host"] = []byte(a)
+				conn["endpoint"] = []byte(a)
 			}
 			if a, ok := attr["username"].(string); ok {
 				conn["username"] = []byte(a)