bug#5642: Reporting a bug loads many Gnus libraries

[Stefan Monnier]

> Current trunk on GNU/Linux:

> emacs -Q
> M-x report-emacs-bug

> Typing C-c C-c to send the bug loads 22 extra libraries, including
> several Gnus ones:

>     gnus-msg gnus-art mm-uu mml2015 epg-config mm-view smime dig gnus-sum
>     nnoo gnus-group gnus-undo nnmail mail-source format-spec gnus-start
>     gnus-spec gnus-int gnus-range gnus-win gnus gnus-ems

I'm not worried about loading more libraries: the change is specifically
to provide more features so extra code is to be expected.  It'd be good
to try and reduce the reliance on Gnus libraries there, tho, or to
rename/restructure them to make it more clear that they're actually
useful independently from the Gnus MUA.

> This extra complexity leads to unexpected bugs like #5299.

Actually, I see no evidence that #5299 is linked to any of
that complexity.


        Stefan