ErrorHandler throws TypeError

[Eslem]

What type of issue are you creating?

• [ ] Bug
• [ ] Enhancement
• [x] Question

What version of this module are you using?

• [ ] 2.0.10 (Stable)
• [ ] 2.1.0-rc.n (2.1 Release Candidate n)
• [x] Other

Write other if any: 2.2.0

When there is no response from the serve throws the error: error.json is not a function, i think the error handler should be:

public handleError(error: Response): any {
    return Observable.throw(error.json? error.json().error : 'Server error');
 }

instead of:

public handleError(error: Response): any {
    return Observable.throw(error.json().error || 'Server error');
  }