Fix missing return statement for reading object attribute values.

Closes #34.

Signed-off-by: Łukasz Dywicki <[email protected]>

api/src/main/java/org/code_house/bacnet4j/wrapper/api/BacNetClientBase.java

@@ -239,6 +239,7 @@ public List<Object> getObjectAttributeValues(BacNetObject object, List<String> p
                     throw new BacNetClientException("Unable to read object properties.", e);
                 }
             }
+            return values;
         }
 
         List<ReadAccessSpecification> specifications = new ArrayList<>();