registry: avoid copy when caps are fixed
registry: avoid copy when caps are fixed

Avoid doing a useless copy when the caps are fixed and simplify will not do
anything.

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