fix(snomed.datastore): Set "concept" as the allowed referenced...

...component type for concrete data type refsets

Author: apeteri

snomed/com.b2international.snowowl.snomed.datastore/src/com/b2international/snowowl/snomed/datastore/request/RefSetSupport.java

@@ -45,7 +45,7 @@ private RefSetSupport() {
 			.put(SnomedRefSetType.ATTRIBUTE_VALUE, SnomedConcept.TYPE)
 			.put(SnomedRefSetType.ATTRIBUTE_VALUE, SnomedDescription.TYPE)
 			.put(SnomedRefSetType.ATTRIBUTE_VALUE, SnomedRelationship.TYPE)
-			.put(SnomedRefSetType.CONCRETE_DATA_TYPE, TerminologyRegistry.UNSPECIFIED)
+			.put(SnomedRefSetType.CONCRETE_DATA_TYPE, SnomedConcept.TYPE)
 			.put(SnomedRefSetType.COMPLEX_MAP, SnomedConcept.TYPE)
 			.put(SnomedRefSetType.COMPLEX_BLOCK_MAP, SnomedConcept.TYPE)
 			.put(SnomedRefSetType.DESCRIPTION_TYPE, SnomedConcept.TYPE)