wireguard: allowedips: remove redundant space

Not a contentful commit, but amusingly found when porting ba3d7b93 to
Windows.

Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Link: https://patch.msgid.link/20260414153944.2742252-4-Jason@zx2c4.com


Signed-off-by: Jakub Kicinski <kuba@kernel.org>