fix double free crash in encoder

fix another issue it will cause encode crash(Issue #477)

int ParseLayerConfig( CReadConfig cRdLayerCfg, const int iLayer, SEncParamExt& pSvcParam )

the cRdLayerCfg is passed by copy construct to a new object, but it do not handle the resource well, so it will cause double free and crash.    replace the object pass by reference, so it can work well on Linux.  

Thanks licaiguo here.