l10n: de.po: improve error message when pushing to unknown upstream
l10n: de.po: improve error message when pushing to unknown upstream

Signed-off-by: Ralf Thielow <d790fea1760bfa57e221e3da971e544c5c4e0598@gmail.com>
Acked-by: Thomas Rast <d9e83874d260f2f10d48d98c0b773b836096d426@thomasrast.ch>

destenson/git,destenson/git,destenson/git,destenson/git,destenson/git,destenson/git,destenson/git,destenson/git