lib/prince.php
public function setAuthScheme($authScheme)
    {
        if(strcasecmp($authScheme, 'http') == 0)
        {
            $this->authScheme = 'http';
        }
        else if(strcasecmp($authScheme, 'https') == 0)
        {
            $this->authScheme = 'https';
        }
        else
        {
            $this->authScheme = '';
        }
    }
public function setAuthScheme($authScheme)
    {
        if(strcasecmp($authScheme, 'http') == 0)
        {
            $this->authScheme = 'http';
        }
        else if(strcasecmp($authScheme, 'https') == 0)
        {
            $this->authScheme = 'https';
        }
        else
        {
            $this->authScheme = '';
        }
    }
Only send USER:PASS for this scheme. (HTTP, HTTPS)