Removed duplicated json data.

There was a duplicated json object for verified-a-sign-up field. So, I removed it. It was making the same button appear twice on the website.

spec/common-self-hosting-auth-sections.json

@@ -123,12 +123,6 @@
         "title": "Returns the updated user",
         "type": "operation"
       },
-      {
-        "id": "verifies-a-sign-up",
-        "slug": "verifies-a-sign-up",
-        "title": "Verifies a sign up",
-        "type": "operation"
-      },
       {
         "id": "verifies-a-sign-up",
         "slug": "verifies-a-sign-up",