Update melpa setup code

core/siren-packages.el

@@ -9,8 +9,20 @@
 (require 'cl)
 (require 'package)
 
-(add-to-list 'package-archives
-             '("melpa" . "http://melpa.org/packages/") t)
+(let* ((no-ssl (and (memq system-type '(windows-nt ms-dos))
+                    (not (gnutls-available-p))))
+       (proto (if no-ssl "http" "https")))
+  (when no-ssl
+    (warn "\
+Your version of Emacs does not support SSL connections,
+which is unsafe because it allows man-in-the-middle attacks.
+There are two things you can do about this warning:
+1. Install an Emacs version that does support SSL and be safe.
+2. Remove this warning from your init file so you won't see it again."))
+  ;; Comment/uncomment these two lines to enable/disable MELPA and MELPA Stable as desired
+  (add-to-list 'package-archives (cons "melpa" (concat proto "://melpa.org/packages/")) t)
+  ;;(add-to-list 'package-archives (cons "melpa-stable" (concat proto "://stable.melpa.org/packages/")) t)
+  )
 
 ;; set package-user-dir to be relative to config path
 (setq package-user-dir (expand-file-name "elpa" siren-dir))