[oe] [Warror][ 12/23] wireguard: Upgrade 20190123 -> 20190406

[Adrian Bunk]

Such an upgrade from the upstream master branch is not appropriate for 
a stable series.

Backporting fixes for 5.1 might be an option, the compile error that was 
posted to the mailing list has a trivial upstream fix.

cu
Adrian

-- 

       "Is there not promise of rain?" Ling Tan asked suddenly out
        of the darkness. There had been need of rain for many days.
       "Only a promise," Lao Er said.
                                       Pearl S. Buck - Dragon Seed