nginx access log shows HEAD request every 5 seconds - django

Question

I have a Django Gunicorn Nginx setup that is working without errors but the nginx access logs contains the following line every 5 seconds:
10.112.113.1 - - [09/Jan/2019:05:02:21 +0100] "HEAD / HTTP/1.1" 302 0 "-" "-"
The amount of information in this logging event is quite scarce, but a 302 every 5 seconds has to be something related to the nginx configuration right?
My nginx configuration is as follows:
http {
log_format main '$remote_addr - $remote_user [$time_local] "$request" '
'$status $body_bytes_sent "$http_referer" '
'"$http_user_agent" "$http_x_forwarded_for"';
access_log /var/log/nginx/access.log main;
sendfile on;
tcp_nopush on;
tcp_nodelay on;
keepalive_timeout 65;
types_hash_max_size 2048;
include /etc/nginx/mime.types;
default_type application/octet-stream;
include /etc/nginx/conf.d/.conf;
upstream app_server {
server unix:/path_to/gunicorn.sock fail_timeout=0;
}
server {
server_name example.com;
listen 80;
return 301 https://example.com$request_uri;
}
server {
listen 443;
listen [::]:443;
server_name example.com;
ssl on;
ssl_certificate /path/cert.crt;
ssl_certificate_key /path/cert.key;
keepalive_timeout 5;
client_max_body_size 4G;
access_log /var/log/nginx/nginx-access.log;
error_log /var/log/nginx/nginx-error.log;
location /static/ {
alias /path_to/static/;
}
location /media/ {
alias /path_to/media/;
}
include /etc/nginx/mime.types;
# checks for static file, if not found proxy to app
location / {
try_files $uri #proxy_to_app;
}
location #proxy_to_app {
proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
proxy_set_header X-Forwarded-Proto https;
proxy_set_header Host $host;
proxy_redirect off;
proxy_pass http://app_server;
}
}
}