Fixed property restriction typo in observable:ContactMessaging

In accordance with CP-5, 'observable:ContactMessaging' should have the
property restriction 'observable:messagingAddress' instead of
'observable:contactAddress'. This commit fixes that typo and wil remove
'observable:messagingAddress' as a potential orphan property.

AJN: This cherry-pick ended up being a manual re-write of the
original patch Trevor authored.  Sorting confused cherry-pick pretty
thoroughly.

References:
* [OC-24] (CP-5) Refactor and improve contacts
* [OC-68] (CP-23) Convert current property restrictions and domain
  assertions to SHACL class shapes

Acked-by: Trevor Bobka <[email protected]>
(cherry picked from commit a402929)

uco-observable/observable.ttl

@@ -1146,12 +1146,12 @@ observable:ContactMessaging
 		[
 			sh:datatype observable:ObservableObject ;
 			sh:maxCount "1"^^xsd:integer ;
-			sh:path observable:contactAddress ;
+			sh:path observable:contactMessagingPlatform ;
 		] ,
 		[
 			sh:datatype observable:ObservableObject ;
 			sh:maxCount "1"^^xsd:integer ;
-			sh:path observable:contactMessagingPlatform ;
+			sh:path observable:messagingAddress ;
 		]
 		;
 	sh:targetClass observable:ContactMessaging ;