Change http link to https.

Author: HonkingGoose

book/A-git-in-other-environments/sections/guis.asc

@@ -148,5 +148,5 @@ However, if your workflow is different, or you want more control over how and wh
 ==== Other GUIs
 
 There are a number of other graphical Git clients, and they run the gamut from specialized, single-purpose tools all the way to apps that try to expose everything Git can do.
-The official Git website has a curated list of the most popular clients at http://git-scm.com/downloads/guis[].
+The official Git website has a curated list of the most popular clients at https://git-scm.com/downloads/guis[].
 A more comprehensive list is available on the Git wiki site, at https://git.wiki.kernel.org/index.php/Interfaces,_frontends,_and_tools#Graphical_Interfaces[].