GitHub exclude (#216)

Github changes their IP continously, and the site is not blocked (except Gist). Force using one IP will easily cause the site fail to load correctly.

snippets/12_ipv4.txt

@@ -53,23 +53,23 @@
 #54.239.130.34 d2dskowxfbo68o.cloudfront.net
 
 ## GitHub
-192.30.253.112 github.com
-192.30.253.113 www.github.com #github.com
-192.30.253.116 api.github.com
-192.30.253.125 live.github.com
-151.101.0.133 assets-cdn.github.com #github.map.fastly.net
-151.101.0.133 collector-cdn.github.com #github.map.fastly.net
-151.101.0.133 pages.github.com #github.map.fastly.net
-151.101.0.133 help.github.com #github.map.fastly.net
-52.70.180.158 collector.githubapp.com
-151.101.0.133 avatars0.githubusercontent.com #github.map.fastly.net
-151.101.0.133 avatars1.githubusercontent.com #github.map.fastly.net
-151.101.0.133 avatars2.githubusercontent.com #github.map.fastly.net
-151.101.0.133 avatars3.githubusercontent.com #github.map.fastly.net
-151.101.0.133 cloud.githubusercontent.com #github.map.fastly.net
-151.101.0.133 camo.githubusercontent.com #github.map.fastly.net
-151.101.0.133 raw.githubusercontent.com #github.map.fastly.net
-151.101.0.133 gist.githubusercontent.com #github.map.fastly.net
+#192.30.253.112 github.com
+#192.30.253.113 www.github.com #github.com
+#192.30.253.116 api.github.com
+#192.30.253.125 live.github.com
+#151.101.0.133 assets-cdn.github.com #github.map.fastly.net
+#151.101.0.133 collector-cdn.github.com #github.map.fastly.net
+#151.101.0.133 pages.github.com #github.map.fastly.net
+#151.101.0.133 help.github.com #github.map.fastly.net
+#52.70.180.158 collector.githubapp.com
+#151.101.0.133 avatars0.githubusercontent.com #github.map.fastly.net
+#151.101.0.133 avatars1.githubusercontent.com #github.map.fastly.net
+#151.101.0.133 avatars2.githubusercontent.com #github.map.fastly.net
+#151.101.0.133 avatars3.githubusercontent.com #github.map.fastly.net
+#151.101.0.133 cloud.githubusercontent.com #github.map.fastly.net
+#151.101.0.133 camo.githubusercontent.com #github.map.fastly.net
+#151.101.0.133 raw.githubusercontent.com #github.map.fastly.net
+#151.101.0.133 gist.githubusercontent.com #github.map.fastly.net
 192.30.253.119 gist.github.com
 
 ## SoundCloud