start-jupyter: support older versions of bash

start-jupyter

@@ -319,11 +319,14 @@ function launch_browser() {
             open "${url}" || show_url "${url}"
             ;;
         Linux)
-            if [[ "$(uname -a)" == *@(Microsoft|WSL)* ]]; then
-                cmd.exe /c start "${url}" || show_url "${url}"
-            else
-                xdg-open "${url}" || show_url "${url}"
-            fi
+            case "$(uname -a)" in
+                *Microsoft*|*WSL*)
+                    cmd.exe /c start "${url}" || show_url "${url}"
+                    ;;
+                *)
+                    xdg-open "${url}" || show_url "${url}"
+                    ;;
+            esac
             ;;
         *)
             show_url "${url}"