Agenda breaks when "home" is in org-gtd-directory twice

[graven04]

If for you 'org-gtd-directory' you have a folder path that contains "home" twice or more eg: /home/user/emacs-29/home/org-files/gtd/org-gtd you get the following message when using command org-gtd-mode:

Non-existent agenda file ~/emacs-29/home/org-files/gtd/org-gtd. [R]emove from list or [A]bort?

This completely breaks the agenda view and no org-agenda output is displayed. if you "R" it just shows up again endlessly and if you abort, well you abort so no org-agenda.

This is a very niche error. I don't think it needs fixing maybe just a little warning in docs.