multiqueue: Allow growing a queue if all other queues are not linked
multiqueue: Allow growing a queue if all other queues are not linked

See https://bugzilla.gnome.org/show_bug.cgi?id=719893

cfoch/gstreamer,centricular/gstreamer,surround-io/gstreamer,centricular/gstreamer,shelsonjava/gstreamer,jpakkane/gstreamer,StreamUtils/gstreamer,surround-io/gstreamer,centricular/gstreamer,ensonic/gstreamer,surround-io/gstreamer,mparis/gstreamer,cablelabs/gstreamer,ensonic/gstreamer,jpxiong/gstreamer,cablelabs/gstreamer,ensonic/gstreamer,cfoch/gstreamer,jpxiong/gstreamer,krichter722/gstreamer,Lachann/gstreamer,mparis/gstreamer,jpakkane/gstreamer,jpakkane/gstreamer,StreamUtils/gstreamer,cablelabs/gstreamer,cfoch/gstreamer,shelsonjava/gstreamer,jpxiong/gstreamer,shelsonjava/gstreamer,krichter722/gstreamer,krichter722/gstreamer,ensonic/gstreamer,centricular/gstreamer,Lachann/gstreamer,mparis/gstreamer,krichter722/gstreamer,cablelabs/gstreamer,surround-io/gstreamer,jpakkane/gstreamer,mparis/gstreamer,Lachann/gstreamer,shelsonjava/gstreamer,Lachann/gstreamer,krichter722/gstreamer,StreamUtils/gstreamer,surround-io/gstreamer,jpakkane/gstreamer,shelsonjava/gstreamer,cablelabs/gstreamer,jpxiong/gstreamer,jpxiong/gstreamer,mparis/gstreamer,StreamUtils/gstreamer,centricular/gstreamer,cfoch/gstreamer,cfoch/gstreamer,Lachann/gstreamer,ensonic/gstreamer,StreamUtils/gstreamer