docs(vignette): remove a supernumerary whitespace in param_optim

vignettes/V02.1_param_optim.Rmd

@@ -113,7 +113,7 @@ For each starting point, a local optimization is performed.
 
 ```{r, warning=FALSE, results='hide', eval=FALSE}
 startGR4JDistrib <- TransfoParam_GR4J(ParamIn = CalibOptions$StartParamDistrib,
-                                       Direction = "RT")
+                                      Direction = "RT")
 startGR4J <- expand.grid(data.frame(startGR4JDistrib))
 optPORT_ <- function(x) {
   opt <- stats::nlminb(start = x,