Processed: fix bug severities

[Debian Bug Tracking System]

Processing commands for control at bugs.debian.org:

> severity 920894 serious
Bug #920894 [src:apriltag] apriltag ftbfs on release architectures
Severity set to 'serious' from 'important'
> severity 918329 important
Bug #918329 [gcc-8] apriltag ftbfs on release architectures
Severity set to 'important' from 'serious'
> thanks
Stopping processing here.

Please contact me if you need assistance.
-- 
918329: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=918329
920894: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=920894
Debian Bug Tracking System
Contact owner at bugs.debian.org with problems