gpush: remove support for legacy from:to syntax


commit 14431b408 introduced the new syntax and warnings about use of the
legacy syntax six years ago, which really should be enough.

Change-Id: Ieeedb8fe85a79a108e654c9ba9f7464789735b61
Reviewed-by: Alexandru Croitor <alexandru.croitor@qt.io>
commit79c4202c178aba84bf0c001fe5c713dcf075978d
parent58a2bcd28cce5407dbab3adbc7d0b9524d59caf9
authorOswald Buddenhagen <oswald.buddenhagen@gmx.de>
committerOswald Buddenhagen <oswald.buddenhagen@gmx.de>
commit timeTue, 9 Jan 2024 16:40:17 +0000