fix: objectMapper creation in FhirTest class

Author: cmark

fhir/com.b2international.snowowl.fhir.rest.tests/src/com/b2international/snowowl/fhir/tests/FhirTest.java

@@ -39,7 +39,7 @@ public class FhirTest {
 
 	protected static final String TEST_DATE_STRING = "2018-03-23T07:49:40.000+0000"; //$NON-NLS-N$
 
-	protected static final ObjectMapper objectMapper = new SnowOwlApiConfig().objectMapper();
+	protected static final ObjectMapper objectMapper = new SnowOwlApiConfig().createObjectMapper();
 
 	@Rule
 	public ExpectedException exception = ExpectedException.none();