Drop package content extra option

This was originaly introduced to allow local packages to be installed.
It was later replaced with localrepo and was marked as obsoleted for
long time.
6 jobs for drop-obsolete in 2 minutes and 59 seconds (queued for 5 seconds)
Status Job ID Name Coverage
  Test
passed #226050
cppcheck

00:00:34

passed #226051
luacheck

00:00:34

passed #226048
system-tests

00:01:38

passed #226049
system-valgrind-tests

00:02:58

passed #226046
unit-tests

00:01:33

passed #226047
unit-valgrind-tests

00:02:46