pidgin/pidgin

Update COPYRIGHT file
release-2.x.y
2022-05-10, Richard Laager
758a7925a920
Update COPYRIGHT file

I audited the Copyright lines in Pidgin 2. This brings the COPYRIGHT
file in line.

Reviewed at https://reviews.imfreedom.org/r/1425/
For information on writing a plugin for Purple, Pidgin or Finch, go
http://developer.pidgin.im and click on API. From there, see the
HOWTOs in the "Related Pages" section.
You can also generate this documentation locally by installing
doxygen and graphviz dot, then running "make docs" in the
source tree. The documentation will be in the docs/html directory.