rgl update on CRAN seems to have modified the rgl example

[cderv]

Here is the diff after having upgraded to rgl 0.103.5

 \hlstd{knit_hooks}\hlopt{$}\hlkwd{set}\hlstd{(}\hlkwc{rgl} \hlstd{= hook_rgl)}
 \hlkwd{head}\hlstd{(hook_rgl)}  \hlcom{# the hook function is defined as this}
 \end{alltt}
 \begin{verbatim}
-##                                                 
-## 1 function (before, options, envir)             
-## 2 {                                             
-## 3     if (before) {                             
-## 4         newwindow <- options$rgl.newwindow    
-## 5         if (!is.null(newwindow) && newwindow) 
-## 6             open3d()
+##                                     
+## 1 function (before, options, envir) 
+## 2 {                                 
+## 3     if (before) {                 
+## 4         do_newwindow(options)     
+## 5         return()                  
+## 6     }
 \end{verbatim}
 \end{kframe}
 \end{knitrout}

There was a modification in rgl, but not announced in NEWS https://github.com/cran/rgl/blame/42a757711d47ba7bd25896e886cea2659e3479a3/R/Sweave_knitr.R#L129

Example need to be updated https://github.com/yihui/knitr/runs/1454400827#step:11:1819