Code refactoring of hawkbit-mgmt (#2055)

Signed-off-by: Avgustin Marinov <Avgustin.Marinov@bosch.com>

hawkbit-mgmt/hawkbit-mgmt-server/src/main/java/org/eclipse/hawkbit/app/mgmt/ErrorController.java

@@ -65,4 +65,4 @@ public class ErrorController extends BasicErrorController {
         }
         return body;
     }
-}
+}

hawkbit-mgmt/hawkbit-mgmt-server/src/main/java/org/eclipse/hawkbit/app/mgmt/MgmtServerStart.java

@@ -48,7 +48,5 @@ public class MgmtServerStart {
 
     @Configuration
     @EnableGlobalMethodSecurity(prePostEnabled = true, securedEnabled = true, proxyTargetClass = true)
-    public static class MethodSecurityConfig {
-
-    }
-}
+    public static class MethodSecurityConfig {}
+}