pidgin/pidgin

Install our appdata file to $(datadir)/metainfo as that change was made a long time ago

This patch originates from Lars Wendler from Gentoo

https://gitweb.gentoo.org/repo/gentoo.git/commit/net-im/pidgin/files/pidgin-2.13.0-metainfo.patch?id=2dd6c1852251b5b67c3045badf173be9535b97a9

Testing Done:
Installed to a prefix and verified the file ended up in `$prefix/share/metainfo`

Reviewed at https://reviews.imfreedom.org/r/607/
# vi:et:ts=2 sw=2 sts=2
image: pidgin/builder-debian:buster
pipelines:
default:
- step:
script:
- set -ex
- meson -Dsilc=false -Ddoc=true -Ddebug=true build
- ninja -C build
- ninja -C build test
branches:
release-2.x.y:
- step:
image: pidgin/builders-2:debian-buster-amd64
script:
- set -ex
- hg clone https://bitbucket.org/pidgin/libgnt -b release-2.x.y
- meson -Dprefix=/usr libgnt libgnt/build
- ninja -C libgnt/build install
- ldconfig
- build.sh