This commit removes the 'CookieJar::get_private_pending()' method in
favor of the already existing and correct 'CookieJar::get_pending()'
method. Previously, the 'CookieJar::get_private_pending()' method
attempted to decrypt the value of a pending cookie, which in reality is
plaintext, thus failing. Because the pending value is plaintext, the
'CookieJar::get_pending()' method suffices.
Documentation has been updated to refer to 'CookieJar::get_pending()'.
Fixes#2063.
arlecchino