Easy start script: add manual xstartup choice

builder/startup/deb/kasmvncserver-easy-start

@@ -7,13 +7,15 @@ interface=0.0.0.0
 cert_group=ssl-cert
 xstartup_script=~/.vnc/xstartup
 
+manual_xstartup_choice="Manually edit xstartup"
 declare -A all_desktop_environments=(
   [Cinnamon]=cinnamon-session
   [Mate]="XDG_CURRENT_DESKTOP=MATE dbus-launch --exit-with-session mate-session"
   [LXDE]=lxsession [Lxqt]=startlxqt
   [KDE]=startkde
   [Gnome]="XDG_CURRENT_DESKTOP=GNOME dbus-launch --exit-with-session /usr/bin/gnome-session"
-  [XFCE]=xfce4-session)
+  [XFCE]=xfce4-session
+  [$manual_xstartup_choice]="")
 detected_desktop_environments=()
 declare -A numbered_desktop_environments
 
@@ -36,6 +38,11 @@ print_detected_desktop_environments() {
 
 detect_desktop_environments() {
   for de_name in "${!all_desktop_environments[@]}"; do
+    if [[ "$de_name" = "$manual_xstartup_choice" ]]; then
+      detected_desktop_environments+=("$de_name")
+      continue;
+    fi
+
     local executable=${all_desktop_environments[$de_name]}
     executable=($executable)
     executable=${executable[-1]}