Fix expected error code.

500 is a server error.  0 is a failed connection.  This should be a server error.

hapi-fhir-structures-r5/src/test/java/ca/uhn/fhir/rest/client/GenericClientTest.java

@@ -436,7 +436,7 @@ public class GenericClientTest {
 				.encodedJson()
 				.execute();
 		} catch (FhirClientConnectionException e) {
-			assertEquals(0, e.getStatusCode());
+			assertEquals(500, e.getStatusCode());
 			assertThat(e.getMessage(), containsString("Failed to parse response from server when performing DELETE to URL"));
 		}