Revert change to eww-suggest-uris

Revert change to eww-suggest-uris

The introduced append is ugly and can yield '(nil); doing delq on it
would be hacks on hacks.
* lisp/net/eww.el: Require cl-lib at run time.
(eww-suggest-uris): Restore eww-current-url, reverting previous change.
(eww): Remove erroneous append.
(eww-open-in-new-buffer): Check if the return from eww-suggested-uris is
equal to eww-current-url, which is nil anyways if we are not in an EWW
buffer.