queue2: Only update current level if we already downloaded a range
queue2: Only update current level if we already downloaded a range

Otherwise queue->level is NULL and dereferencing that is not a good
idea in general.

https://bugzilla.gnome.org/show_bug.cgi?id=707648

mparis/gstreamer,krichter722/gstreamer,lovebug356/gstreamer,surround-io/gstreamer,jpxiong/gstreamer,justinjoy/gstreamer,jpxiong/gstreamer,shelsonjava/gstreamer,justinjoy/gstreamer,lovebug356/gstreamer,jpxiong/gstreamer,cablelabs/gstreamer,krieger-od/gstreamer,centricular/gstreamer,shelsonjava/gstreamer,lubosz/gstreamer,cablelabs/gstreamer,lovebug356/gstreamer,ensonic/gstreamer,cfoch/gstreamer,StreamUtils/gstreamer,jpxiong/gstreamer,surround-io/gstreamer,cfoch/gstreamer,lovebug356/gstreamer,Lachann/gstreamer,ensonic/gstreamer,Lachann/gstreamer,cablelabs/gstreamer,shelsonjava/gstreamer,mparis/gstreamer,surround-io/gstreamer,justinjoy/gstreamer,cfoch/gstreamer,centricular/gstreamer,lubosz/gstreamer,mparis/gstreamer,jpakkane/gstreamer,ensonic/gstreamer,shelsonjava/gstreamer,centricular/gstreamer,shelsonjava/gstreamer,ensonic/gstreamer,Lachann/gstreamer,lubosz/gstreamer,jpxiong/gstreamer,surround-io/gstreamer,Lachann/gstreamer,ensonic/gstreamer,justinjoy/gstreamer,StreamUtils/gstreamer,krieger-od/gstreamer,krieger-od/gstreamer,justinjoy/gstreamer,krieger-od/gstreamer,cablelabs/gstreamer,centricular/gstreamer,centricular/gstreamer,StreamUtils/gstreamer,jpakkane/gstreamer,cfoch/gstreamer,surround-io/gstreamer,krichter722/gstreamer,krichter722/gstreamer,krichter722/gstreamer,krieger-od/gstreamer,Lachann/gstreamer,jpakkane/gstreamer,lubosz/gstreamer,StreamUtils/gstreamer,cablelabs/gstreamer,mparis/gstreamer,mparis/gstreamer,cfoch/gstreamer,lovebug356/gstreamer,jpakkane/gstreamer,lubosz/gstreamer,krichter722/gstreamer,StreamUtils/gstreamer,jpakkane/gstreamer