Documentation: replace git protocol with https

git protocol will be retired by GitHub soon.
Replace it with supported https instead.

CONTRIBUTING.md

@@ -20,7 +20,7 @@ To get started, [fork](https://help.github.com/articles/fork-a-repo) the void-li
 
 To keep your forked repository up to date, setup the `upstream` remote to pull in new changes:
 
-    $ git remote add upstream git://github.com/void-linux/void-packages.git
+    $ git remote add upstream https://github.com/void-linux/void-packages.git
     $ git pull --rebase upstream master
 
 ### Creating a new template

Manual.md

@@ -2124,7 +2124,7 @@ a github pull request.
 To keep your forked repository always up to date, setup the `upstream` remote
 to pull in new changes:
 
-    $ git remote add upstream git://github.com/void-linux/void-packages.git
+    $ git remote add upstream https://github.com/void-linux/void-packages.git
     $ git pull --rebase upstream master
 
 <a id="help"></a>

README.md

@@ -59,7 +59,7 @@ methods.
 Clone the `void-packages` git repository and install the bootstrap packages:
 
 ```
-$ git clone git://github.com/void-linux/void-packages.git
+$ git clone https://github.com/void-linux/void-packages.git
 $ cd void-packages
 $ ./xbps-src binary-bootstrap
 ```
@@ -441,7 +441,7 @@ try other [chroot methods](#chroot-methods).
 
 Clone the `void-packages` git repository:
 
-    $ git clone git://github.com/void-linux/void-packages
+    $ git clone https://github.com/void-linux/void-packages.git
 
 and `xbps-src` should be fully functional; just start the `bootstrap` process, i.e: