[emacs-w3m:13574] Recent emacs build made w3m-search slow to load

Dear Bug Team!

Yesterday I compiled a new version of emacs. Having done so, starting
emacs was very slow compared to the previous compile. (with new compile
I don't mean I know it is due to the new binary, its just what
happened). I bisected my .emacs and if commenting this out

----------------------------------8<----------------------------------
(use-package w3m-search
  :config
  (add-to-list 'w3m-search-engine-alist
               '("duck" "https://duckduckgo.com/lite/?q=%s"))
  (setq w3m-search-default-engine "duck"))
---------------------------------->8----------------------------------

startup time is 1.8 seconds and if un-commenting it, it is 26.1 seconds.
Can you help me debug this?

Emacs repository revision: 15ed1598b5e8aacea2825e6144cb3cce35101134

For information, this was evident with my previous version of emacs-w3m
and also after an update of emacs-w3m I did yesterday.

Best regards
--
Tomas

================================================================

System Info to help track down your bug:
---------------------------------------
emacs-w3m-git-revision
 => "361297e"
emacs-w3m-version
 => "1.4.632"
emacs-version
 => "GNU Emacs 27.0.50 (build 1, x86_64-pc-linux-gnu, GTK+ Version 3.24.5)\n of 2019-10-14"
mule-version
 => "6.0 (HANACHIRUSATO)"
system-type
 => gnu/linux
(featurep 'gtk)
 => t
(featurep 'w3m-load)
 => t
w3m-version
 => "w3m/0.5.3+git20190105"
w3m-type
 => w3m-m17n
w3m-compile-options
 => ("lang=en" "m17n" "image" "color" "ansi-color" "mouse" "gpm" "menu" "cookie" "ssl" "ssl-verify" "external-uri-loader" "w3mmailer" "nntp" "gopher" "ipv6" "alarm" "mark" "migemo")
w3m-language
 => nil
w3m-command-arguments
 => nil
w3m-command-arguments-alist
 => nil
w3m-command-environment
 => (("LC_ALL" . "C"))
w3m-input-coding-system
 => utf-8
w3m-output-coding-system
 => utf-8