GH-2241 - Never return null for empty collections.

There could be the case that for collections instead of an empty
instance, SDN would return null.
This was because the value were never touched for setting.
Also this was not deterministic because it was depending on the
random order the properties of an entity were processed.

Closes #2241

Author: meistermeier

src/main/java/org/springframework/data/neo4j/core/mapping/DefaultNeo4jEntityConverter.java

@@ -474,10 +474,6 @@ private Optional<Object> createInstanceOfRelationships(Neo4jPersistentProperty p
 					.filter(n -> n.hasLabel(targetLabel)).collect(Collectors.toList())
 					.forEach(allNodesWithMatchingLabelInResult::add);
 
-			if (allNodesWithMatchingLabelInResult.isEmpty() || allMatchingTypeRelationshipsInResult.isEmpty()) {
-				return Optional.empty();
-			}
-
 			Function<Relationship, Long> targetIdSelector = relationshipDescription.isIncoming() ? Relationship::startNodeId : Relationship::endNodeId;
 			Function<Relationship, Long> sourceIdSelector = relationshipDescription.isIncoming() ? Relationship::endNodeId : Relationship::startNodeId;
 			Long sourceNodeId = getInternalId(values);