TwitterKit dissmiss viewcontroller modally

Question

In project I am using "TwitterKit" for twitter login. I am using below code in my project:

TWTRTwitter.sharedInstance().logIn {(session, error) in
  if let s = session {
    print("logged in user with id \(session.userID)")
  } else {
    // log error
  }
}

The above code works fine if "Twitter" app is installed in my device. But the problem occurs if there is no "Twitter" app is installed in the device. And the problem is that, my viewcontroller got dismissed modally to the root. I have provided all the required stuffs in the .plist and the appdelegate class.

Can any one please suggest me how can I get rid of from this problem?