lib/updater: fix invalid hash check for SHA256

This is major problem as packages were not verified thanks to this
error.

This also adds warning for packages not correctly verified.
6 jobs for v61.1.5.3 in 2 minutes and 39 seconds (queued for 5 seconds)
latest
Status Job ID Name Coverage
  Test
passed #378877
cppcheck

00:00:41

passed #378878
luacheck

00:00:36

passed #378875
system-tests

00:01:05

passed #378876
system-valgrind-tests

00:02:39

passed #378873
unit-tests

00:01:01

passed #378874
unit-valgrind-tests

00:02:25