Set rsvg as default SVG post-processing: rsvg2 is broken on shiny…

…apps.io

* It is somehow broken for new deployments, but still works locally.
* No big deal for the live app to use `rsvg`, also given that InkScape-based post-processing have always been broken there.

R/rTRNG-stickR-app.R

@@ -176,7 +176,7 @@ ui <- function() {
             12,
             radioButtons("svg_postprocess", label = NULL, inline = TRUE,
                          choices = c("as-is", "rsvg", "rsvg2", "inkscape", "inkscape-text2path"),
-                         selected = "rsvg2")
+                         selected = "rsvg")
           )
         ),