Fixed the issue regarding error if a folder defined in src_folders is empty when using tags

[itsspriyansh]

The error originates in the function applyTagFilter which lies in folder-walk.js
The cause of the error is that when any folder that is defined in src_folders in the file nightwatch.conf.js, is empty, the list parameter of the function applyTagFilter goes undefined. When the function executes, it uses the Array property .map() on list parameter which is undefined and hence the error.

To fix this, an if condition is added to the top of the function body which returns the function if the parameter list doesn't qualify as an array.

Fixes: #3823

[github-actions]

Status

• ❌ No modified files found in the types directory.
  Please make sure to include types for any changes you have made. Thank you!.