Fix javadoc reference to Field.

Closes #1293.

Author: mikereiche

src/main/java/org/springframework/data/couchbase/repository/query/support/N1qlUtils.java

@@ -26,6 +26,7 @@
 import org.springframework.data.couchbase.core.convert.CouchbaseConverter;
 import org.springframework.data.couchbase.core.mapping.CouchbasePersistentEntity;
 import org.springframework.data.couchbase.core.mapping.CouchbasePersistentProperty;
+import org.springframework.data.couchbase.core.mapping.Field;
 import org.springframework.data.couchbase.core.query.N1QLExpression;
 import org.springframework.data.couchbase.core.query.N1QLQuery;
 import org.springframework.data.couchbase.repository.query.CouchbaseEntityInformation;