Use HTTPS for Discourse forum

(cherry picked from commit 1e20218b3d)

README.md

@@ -139,7 +139,7 @@ On [glfw.org](http://www.glfw.org/) you can find the latest version of GLFW, as
 well as news, documentation and other information about the project.
 
 If you have questions related to the use of GLFW, we have a
-[forum](http://discourse.glfw.org/), and the `#glfw` IRC channel on
+[forum](https://discourse.glfw.org/), and the `#glfw` IRC channel on
 [Freenode](http://freenode.net/).
 
 If you have a bug to report, a patch to submit or a feature you'd like to

docs/CONTRIBUTING.md

@@ -20,14 +20,14 @@
 ## Asking a question
 
 Questions about how to use GLFW should be asked either in the [support
-section](http://discourse.glfw.org/c/support) of the forum, under the [Stack
+section](https://discourse.glfw.org/c/support) of the forum, under the [Stack
 Overflow tag](https://stackoverflow.com/questions/tagged/glfw) or [Game
 Development tag](https://gamedev.stackexchange.com/questions/tagged/glfw) on
 Stack Exchange or in the IRC channel `#glfw` on
 [Freenode](http://freenode.net/).
 
 Questions about the design or implementation of GLFW or about future plans
-should be asked in the [dev section](http://discourse.glfw.org/c/dev) of the
+should be asked in the [dev section](https://discourse.glfw.org/c/dev) of the
 forum or in the IRC channel.  Please don't open a GitHub issue to discuss design
 questions without first checking with a maintainer.