remove dangerous dynamic atom creation

Author: peaceful-james

lib/web_push_elixir.ex

@@ -111,8 +111,8 @@ defmodule WebPushElixir do
     vapid_public_key = url_decode(Application.get_env(:web_push_elixir, :vapid_public_key))
     vapid_private_key = url_decode(Application.get_env(:web_push_elixir, :vapid_private_key))
 
-    %{endpoint: endpoint, keys: %{p256dh: p256dh, auth: auth}} =
-      Jason.decode!(subscription, keys: :atoms)
+    %{"endpoint" => endpoint, "keys" => %{"p256dh" => p256dh, "auth" => auth}} =
+      Jason.decode!(subscription)
 
     encrypted_payload = encrypt_payload(message, p256dh, auth)