Remove manifest attributes

These properties are not supported in packaged apps.

manifest.json

@@ -21,11 +21,5 @@
       "background": {
           "page": "background.html"
       }
-    },
-
-    "options_page": "options.html",
-
-  "content_security_policy":
-    "default-src 'self'; img-src 'self' data:; connect-src https://textsecure-service-staging.whispersystems.org wss://textsecure-service-staging.whispersystems.org https://whispersystems-textsecure-attachments-staging.s3.amazonaws.com; style-src 'self' 'unsafe-inline'"
-
+    }
 }