info: Protect __categories list in get_category with lock too
info: Protect __categories list in get_category with lock too

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