dont log social data leak exploit attempts

playbooks/roles/nginx/templates/edx/app/nginx/sites-available/lms.j2

@@ -11,6 +11,11 @@ upstream lms-backend {
 
 }
 
+map $request_uri $loggable {
+    ~/login\?next=favicon\.ico 0;
+    default 1;
+}
+
 {%- if EDXAPP_ENABLE_RATE_LIMITING -%}
 # Make Zone
 limit_req_zone $cookie_{{ EDXAPP_SESSION_COOKIE_NAME }} zone=cookies:10m rate={{ EDXAPP_COURSES_REQUEST_RATE }};
@@ -123,7 +128,7 @@ error_page {{ k }} {{ v }};
   }
   {% endif %}
   
-  access_log {{ nginx_log_dir }}/access.log {{ NGINX_LOG_FORMAT_NAME }};
+  access_log {{ nginx_log_dir }}/access.log {{ NGINX_LOG_FORMAT_NAME }} if=$loggable;
   error_log {{ nginx_log_dir }}/error.log error;
 
   # CS184 requires uploads of up to 4MB for submitting screenshots.