pidgin/pidgin

Add support for the no_proxy environment variable.
release-2.x.y
2021-06-22, Gary Kramlich
2ed8b00673a0
Add support for the no_proxy environment variable.

This started as a patch on https://issues.imfreedom.org/issue/PIDGIN-17518
but I cleaned it up a bit as well.

Testing Done:
Followed the unit tests that are documented in the diff.

Bugs closed: PIDGIN-17518

Reviewed at https://reviews.imfreedom.org/r/667/
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