pidgin/pidgin

Update the ChangeLog and configure.ac for release
release-2.x.y v2.14.2
2021-04-01, Gary Kramlich
2eb25613d054
Update the ChangeLog and configure.ac for release

Testing Done:
Ran `make dist-check` locally.

Reviewed at https://reviews.imfreedom.org/r/590/
installed_m4=purple.m4
EXTRA_DIST=$(installed_m4)
m4datadir=$(datadir)/aclocal
m4data_DATA=$(installed_m4)