class/runit: Allow override of rdepend on runit
class/runit: Allow override of rdepend on runit

Make it possible to set runits rdepends to "". Else problems arise when
using runit.
Also ensure we are in the correct dir.

hundeboll/core,sknsean/core,hundeboll/core,hundeboll/core,diorcety/oe-lite-core,sknsean/core,sknsean/core,hundeboll/core,sknsean/core,sknsean/core,diorcety/oe-lite-core