lib: Fix listing.less to allow nested listing
lib: Fix listing.less to allow nested listing

With this patch, CSS for nested <Listing> elements (i.e. in a tab renderer)
are handled correctly.

Reviewed-by: Dominik Perpeet <f7830b2723a5db4fc185058b06cfab4b89a38da9@redhat.com>

andreasn/cockpit,cockpituous/cockpit,larsu/cockpit,larskarlitski/cockpit,petervo/cockpit,Scribery/cockpit,cockpit-project/cockpit,harishanand95/cockpit,andreasn/cockpit,petervo/cockpit,deryni/cockpit,xhad/cockpit,mvollmer/cockpit,garrett/cockpit,petervo/cockpit,andreasn/cockpit,michalskrivanek/cockpit,harishanand95/cockpit,larskarlitski/cockpit,cockpit-project/cockpit,larskarlitski/cockpit,mareklibra/cockpit,stefwalter/cockpit,Scribery/cockpit,mareklibra/cockpit,stefwalter/cockpit,harishanand95/cockpit,andreasn/cockpit,dperpeet/cockpit,garrett/cockpit,deryni/cockpit,mareklibra/cockpit,michalskrivanek/cockpit,xhad/cockpit,andreasn/cockpit,andreasn/cockpit,larskarlitski/cockpit,stefwalter/cockpit,martinpitt/cockpit,larsu/cockpit,michalskrivanek/cockpit,michalskrivanek/cockpit,xhad/cockpit,deryni/cockpit,deryni/cockpit,mvollmer/cockpit,moraleslazaro/cockpit,mvollmer/cockpit,cockpituous/cockpit,cockpit-project/cockpit,larsu/cockpit,Scribery/cockpit,moraleslazaro/cockpit,dperpeet/cockpit,cockpit-project/cockpit,SotolitoLabs/cockpit,garrett/cockpit,deryni/cockpit,SotolitoLabs/cockpit,xhad/cockpit,SotolitoLabs/cockpit,cockpituous/cockpit,dperpeet/cockpit,harishanand95/cockpit,mvollmer/cockpit,mvollmer/cockpit,SotolitoLabs/cockpit,harishanand95/cockpit,stefwalter/cockpit,mareklibra/cockpit,SotolitoLabs/cockpit,michalskrivanek/cockpit,xhad/cockpit,martinpitt/cockpit,deryni/cockpit,dperpeet/cockpit,petervo/cockpit,moraleslazaro/cockpit,mareklibra/cockpit,dperpeet/cockpit,cockpit-project/cockpit,larskarlitski/cockpit,garrett/cockpit,cockpituous/cockpit,Scribery/cockpit,michalskrivanek/cockpit,moraleslazaro/cockpit,petervo/cockpit,mareklibra/cockpit,martinpitt/cockpit,andreasn/cockpit,harishanand95/cockpit,larsu/cockpit,petervo/cockpit,mareklibra/cockpit,martinpitt/cockpit,larsu/cockpit,moraleslazaro/cockpit,larsu/cockpit,garrett/cockpit,Scribery/cockpit,SotolitoLabs/cockpit,SotolitoLabs/cockpit,Scribery/cockpit,dperpeet/cockpit,deryni/cockpit,stefwalter/cockpit,stefwalter/cockpit,xhad/cockpit,Scribery/cockpit,moraleslazaro/cockpit,larskarlitski/cockpit,dperpeet/cockpit,harishanand95/cockpit,larskarlitski/cockpit,cockpituous/cockpit,moraleslazaro/cockpit,cockpituous/cockpit,michalskrivanek/cockpit,xhad/cockpit,stefwalter/cockpit,petervo/cockpit,martinpitt/cockpit