pwg: remove confusing metadata example with 0.8 code
pwg: remove confusing metadata example with 0.8 code

Fixes #534314.

mrchapp/gstreamer,jpakkane/gstreamer,ylatuya/gstreamer,jpxiong/gstreamer,lovebug356/gstreamer,ahmedammar/platform_external_gst_gstreamer,cfoch/gstreamer,krichter722/gstreamer,ahmedammar/platform_external_gst_gstreamer,magcius/gstreamer,shelsonjava/gstreamer,magcius/gstreamer,magcius/gstreamer,ahmedammar/platform_external_gst_gstreamer,cfoch/gstreamer,drothlis/gstreamer,lubosz/gstreamer,jpxiong/gstreamer,jpxiong/gstreamer,ylatuya/gstreamer,justinjoy/gstreamer,centricular/gstreamer,Lachann/gstreamer,collects/gstreamer,mparis/gstreamer,Lachann/gstreamer,justinjoy/gstreamer,mrchapp/gstreamer,ensonic/gstreamer,ylatuya/gstreamer,krichter722/gstreamer,cablelabs/gstreamer,centricular/gstreamer,ensonic/gstreamer,jpxiong/gstreamer,jpakkane/gstreamer,justinjoy/gstreamer,lubosz/gstreamer,Lachann/gstreamer,lubosz/gstreamer,drothlis/gstreamer,cablelabs/gstreamer,StreamUtils/gstreamer,Lachann/gstreamer,jpxiong/gstreamer,cablelabs/gstreamer,Distrotech/gstreamer,shelsonjava/gstreamer,cfoch/gstreamer,mparis/gstreamer,mparis/gstreamer,lovebug356/gstreamer,jpakkane/gstreamer,mrchapp/gstreamer,cablelabs/gstreamer,cablelabs/gstreamer,ahmedammar/platform_external_gst_gstreamer,krieger-od/gstreamer,StreamUtils/gstreamer,krieger-od/gstreamer,krichter722/gstreamer,krieger-od/gstreamer,mrchapp/gstreamer,StreamUtils/gstreamer,lubosz/gstreamer,magcius/gstreamer,ensonic/gstreamer,magcius/gstreamer,Distrotech/gstreamer,surround-io/gstreamer,collects/gstreamer,justinjoy/gstreamer,surround-io/gstreamer,StreamUtils/gstreamer,surround-io/gstreamer,lovebug356/gstreamer,ylatuya/gstreamer,cfoch/gstreamer,ylatuya/gstreamer,mrchapp/gstreamer,ensonic/gstreamer,centricular/gstreamer,Distrotech/gstreamer,Distrotech/gstreamer,surround-io/gstreamer,mparis/gstreamer,mparis/gstreamer,krieger-od/gstreamer,ensonic/gstreamer,ahmedammar/platform_external_gst_gstreamer,collects/gstreamer,StreamUtils/gstreamer,surround-io/gstreamer,cfoch/gstreamer,krichter722/gstreamer,jpakkane/gstreamer,drothlis/gstreamer,krieger-od/gstreamer,shelsonjava/gstreamer,collects/gstreamer,shelsonjava/gstreamer,collects/gstreamer,krichter722/gstreamer,Distrotech/gstreamer,centricular/gstreamer,drothlis/gstreamer,centricular/gstreamer,lovebug356/gstreamer,Lachann/gstreamer,jpakkane/gstreamer,drothlis/gstreamer,justinjoy/gstreamer,lubosz/gstreamer,shelsonjava/gstreamer,lovebug356/gstreamer