Remove unneeded x-jwks_uri for ID token in swagger.yaml.

Author: wmwong

appengine/endpoints/swagger.yaml

@@ -103,4 +103,3 @@ securityDefinitions:
     flow: "implicit"
     type: "oauth2"
     x-issuer: "accounts.google.com"
-    x-jwks_uri: "https://www.googleapis.com/oauth2/v1/certs"