examples: link testrtpool to pthreads
examples: link testrtpool to pthreads

Fixes #686787

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