Steps to Reproduce

an app handle "page not found" error in ErrorPageInit Initiator by redirecting to the root path "/"
1. visit the root path
2. the welcome-file enforces to visit /index.zul
3. no index.zul exists in the app, go back to step 1

Current Result

infinite redirect

Expected Result

don't enforce to visit index.zul by default

Debug Information

• propose to remove <welcome-file-list> in zkwebfragment.jar
  <welcome-file-list>
  <welcome-file>index.zul</welcome-file>
  <welcome-file>index.zhtml</welcome-file>
  </welcome-file-list>
  Since <welcome-file-list> is quite application-dependent. It's hard for app developers to know there is a setting in zkwebfragment.jar when debugging.