fixed test

core/src/test/java/dev/fitko/fitconnect/core/validation/DefaultValidationServiceTest.java

@@ -161,7 +161,7 @@ class DefaultValidationServiceTest {
 
         // Then
         assertTrue(validationResult.hasError());
-        assertThat(validationResult.getError().getMessage(), containsString("\"certChain\" is null"));
+        assertThat(validationResult.getError().getMessage(), containsString("\"x5c\" is null"));
     }