rtp: Re-add plugin ldflags
rtp: Re-add plugin ldflags

pexip/farstream,ahmedammar/skype_farsight2,kakaroto/farstream,pexip/farstream,shadeslayer/farstream,tieto/farstream,shadeslayer/farstream,tieto/farstream,kakaroto/farstream,kakaroto/farstream,ahmedammar/skype_farsight2,tieto/farstream,pexip/farstream,shadeslayer/farstream,ahmedammar/skype_farsight2,tieto/farstream,tieto/farstream,kakaroto/farstream,shadeslayer/farstream,pexip/farstream,ahmedammar/skype_farsight2