Fixed docs.

docs/build.rst

@@ -13,9 +13,9 @@ Getting Source
 
 ::
 
-    git clone git://github.com/bkaradzic/bx.git
-    git clone git://github.com/bkaradzic/bimg.git
-    git clone git://github.com/bkaradzic/bgfx.git
+    git clone https://github.com/bkaradzic/bx.git
+    git clone https://github.com/bkaradzic/bimg.git
+    git clone https://github.com/bkaradzic/bgfx.git
 
 Quick Start
 -----------