d/copyright: license on client/* is GPL-2+
Upstream commit 27e37a50 relicensed this to GPL-2+ to fix the license incompatibility with GPL-3+ releases of libreadline.
Closes: #979100
Upstream commit 27e37a50 relicensed this to GPL-2+ to fix the license incompatibility with GPL-3+ releases of libreadline.
Closes: #979100