Remove ecommerce from nginx_sites in edx_sandbox.yml.

Since #3994 is merged, the nginx configuration of ecommerce is handled by the
ecommerce role itself (via the edx_django_service role).

playbooks/edx_sandbox.yml

@@ -33,7 +33,6 @@
       - lms
       - forum
       - xqueue
-      - ecommerce
       nginx_default_sites:
       - lms
     - role: edxlocal