Support both single and double brackets in code-server's URI template (#934)

* Update vsc.R

*  Modify url to allow proxied requests

* Minor update

* Fix message for webview

* Support both single and double brackets

Co-authored-by: Kun Ren <[email protected]>

Author: benz0li

R/session/vsc.R

@@ -516,7 +516,7 @@ show_browser <- function(url, title = url, ...,
   if (nzchar(proxy_uri)) {
     is_base_path <- grepl("\\:\\d+$", url)
     url <- sub("^https?\\://(127\\.0\\.0\\.1|localhost)(\\:)?",
-      sub("{port}", "", proxy_uri, fixed = TRUE), url)
+      sub("\\{\\{?port\\}\\}?", "", proxy_uri), url)
     if (is_base_path) {
       url <- paste0(url, "/")
     }
@@ -573,7 +573,7 @@ show_webview <- function(url, title, ..., viewer) {
   if (nzchar(proxy_uri)) {
     is_base_path <- grepl("\\:\\d+$", url)
     url <- sub("^https?\\://(127\\.0\\.0\\.1|localhost)(\\:)?",
-      sub("{port}", "", proxy_uri, fixed = TRUE), url)
+      sub("\\{\\{?port\\}\\}?", "", proxy_uri), url)
     if (is_base_path) {
       url <- paste0(url, "/")
     }