Created Unassigned: Underscores into user images [2637]

Hi,
I think there is some problem when the library returns the path (ProfileImageFullSizeUrl) of a user.
In particular, the error is present when the original url has an underscore.
Seems the library lose the underscore returning a wrong image path.

ie:

Trying to receive the Demi Lovato's image:

var user = Tweetinvi.User.GetUserFromScreenName("ddlovato");
var imageUrl = user.ProfileImageFullSizeUrl;

the variable imageUrl returned is "http://pbs.twimg.com/profile_images/614150024847605760/HrQVHpR.png"
while the current and correct url on Twitter is "https://pbs.twimg.com/profile_images/614150024847605760/HrQVHpR_.png"

Thank you.
Stefano