Reverted changes to ecommerce-related gunicorn files

#2388 and #2393 introduced changes to gunicorn.py that prevent these services from starting.

ECOM-2594

playbooks/roles/ansible-role-django-ida/templates/templates/edx/app/ROLE_NAME/ROLE_NAME_gunicorn.py.j2

@@ -9,15 +9,4 @@ pythonpath = "{{ '{{' }} {{ role_name }}_code_dir }}"
 workers = {{ '{{' }} {{ role_name|upper }}_GUNICORN_WORKERS }}
 worker_class = "{{ '{{' }} {{ role_name|upper }}_GUNICORN_WORKER_CLASS }}"
 
-def post_fork(server, worker):
-    """
-    Close the cache so that newly forked workers cannot accidentally share the
-    socket with the processes they were forked from. This prevents a race
-    condition in which one worker could get a cache response intended for
-    another worker.
-    """
-    from django.core.cache import cache
-    if hasattr(cache, 'close'):
-        cache.close()
-
 {{ '{{' }} {{ role_name|upper }}_GUNICORN_EXTRA_CONF }}

playbooks/roles/ecommerce/templates/edx/app/ecommerce/ecommerce_gunicorn.py.j2

@@ -9,15 +9,4 @@ pythonpath = "{{ ecommerce_code_dir }}"
 workers = {{ ECOMMERCE_GUNICORN_WORKERS }}
 worker_class = "{{ ECOMMERCE_GUNICORN_WORKER_CLASS }}"
 
-def post_fork(server, worker):
-    """
-    Close the cache so that newly forked workers cannot accidentally share the
-    socket with the processes they were forked from. This prevents a race
-    condition in which one worker could get a cache response intended for
-    another worker.
-    """
-    from django.core.cache import cache
-    if hasattr(cache, 'close'):
-        cache.close()
-
 {{ ECOMMERCE_GUNICORN_EXTRA_CONF }}

playbooks/roles/programs/templates/edx/app/programs/programs_gunicorn.py.j2

@@ -9,15 +9,4 @@ pythonpath = "{{ programs_code_dir }}"
 workers = {{ PROGRAMS_GUNICORN_WORKERS }}
 worker_class = "{{ PROGRAMS_GUNICORN_WORKER_CLASS }}"
 
-def post_fork(server, worker):
-    """
-    Close the cache so that newly forked workers cannot accidentally share the
-    socket with the processes they were forked from. This prevents a race
-    condition in which one worker could get a cache response intended for
-    another worker.
-    """
-    from django.core.cache import cache
-    if hasattr(cache, 'close'):
-        cache.close()
-
 {{ PROGRAMS_GUNICORN_EXTRA_CONF }}