Commit ba798d7578a4e036ee657b76bbdcfa79404cf1b3 broke sharing via Telegram for me. It requires the desktop entry to contain the substring -- @@u %u @@, but for me desktop entry contains only Exec=telegram-desktop -- %u. Upstream .desktop file also doesn't contain those @@.
This commit reverts the behavior of preprocessing the command line to the old version.
By the way, I don't really know why @@u -> @@ replacement is needed. When can it appear in the desktop file for Telegram?