Still errors with Emacs 26.3

[Axel Kielhorn]

Thanks for fixing the errors in org cite.

I still get the following messages with 3664447eb when building with Emacs 26.3.


Compiling /Users/axel/src/Emacs/org-mode/lisp/org-agenda.el...

In end of data:
org-agenda.el:10873:1:Warning: the function ‘string-empty-p’ is not known to
    be defined.

Compiling /Users/axel/src/Emacs/org-mode/lisp/org-plot.el...

In org-plot/gnuplot:
org-plot.el:634:4:Warning: ‘(dump-func (plist-get type :data-dump))’ is a
    malformed function
org-plot.el:685:17:Warning: reference to free variable ‘dump-func’

In end of data:
org-plot.el:731:1:Warning: the function ‘if-let’ is not known to be defined.

Compiling /Users/axel/src/Emacs/org-mode/lisp/org-src.el...

In org-edit-src-save:
org-src.el:1207:16:Warning: replace-buffer-contents called with 3 arguments,
    but accepts only 1

In org-edit-src-exit:
org-src.el:1255:17:Warning: replace-buffer-contents called with 3 arguments,
    but accepts only 1

Greetings
Axel