Add docs on how to turn off SSL verification on GH oauth

In gitlab-ee!323 we added support to disable SSL verification because attempting to import projects from a self-signed GH Enterprise instance will fail with an SSL error.

doc/integration/github.md

@@ -118,32 +118,28 @@ It should be disabled by adding `verify_ssl` to `false` to the provider configur
 For omnibus package:
-    For GitHub Enterprise:
-
-    ```ruby
-      gitlab_rails['omniauth_providers'] = [
-        {
-          "name" => "github",
-          "app_id" => "YOUR_APP_ID",
-          "app_secret" => "YOUR_APP_SECRET",
-          "url" => "https://github.com/",
-          "verify" => false,
-          "args" => { "scope" => "user:email" }
-        }
-      ]
-    ```
+```ruby
+  gitlab_rails['omniauth_providers'] = [
+    {
+      "name" => "github",
+      "app_id" => "YOUR_APP_ID",
+      "app_secret" => "YOUR_APP_SECRET",
+      "url" => "https://github.com/",
+      "verify_ssl" => false,
+      "args" => { "scope" => "user:email" }
+    }
+  ]
+```
 For installation from source:
-    For GitHub Enterprise:
-
-    ```
-      - { name: 'github', app_id: 'YOUR_APP_ID',
-        app_secret: 'YOUR_APP_SECRET',
-        url: "https://github.example.com/",
-        verify: false,
-        args: { scope: 'user:email' } }
-    ```
+```
+  - { name: 'github', app_id: 'YOUR_APP_ID',
+    app_secret: 'YOUR_APP_SECRET',
+    url: "https://github.example.com/",
+    verify_ssl: false,
+    args: { scope: 'user:email' } }
+```
 For the changes to take effect, [reconfigure Gitlab] if you installed