我有以下Nginx配置。我将所有HTTP请求重定向到HTTPS。我要实现的是，robots.txt（“ http://example.com/robots.txt”或“ http://example2.com/robots.txt”）上的HTTP请求将不会重定向到HTTPS。我很难找到合适的陈述。

我的Nginx配置

server {

    server_name  example.com  www.example.com  example2.com  www.example2.com;

    proxy_set_header X-Real-IP $remote_addr;
    proxy_set_header HOST $http_host;
    proxy_set_header        X-Forwarded-For $proxy_add_x_forwarded_for;
    proxy_set_header        X-Forwarded-Proto $scheme;
    proxy_set_header X-HTTPS-Protocol $ssl_protocol;
    proxy_set_header X-NginX-Proxy true;

    location / {
        proxy_pass http://127.0.0.1:9092;
    }

    listen 443 ssl;
    ssl_certificate /path
    ssl_certificate_key /path
    include /path
    ssl_dhparam /path



}
server {

    server_name  example.com  www.example.com  example2.com  www.example2.com;

    listen 80;
    listen [::]:80;

    #
    # What to put here not to redirect robots.txt to HTTPS?
    #

    if ($host = www.example.com) {
        return 301 https://$host$request_uri;
    }

    if ($host = example.com) {
        return 301 https://$host$request_uri;
    }

    if ($host = www.example2.com) {
        return 301 https://$host$request_uri;
    }

    if ($host = example2.com) {
        return 301 https://$host$request_uri;
    }

    proxy_set_header X-Real-IP $remote_addr;
    proxy_set_header HOST $http_host;
    proxy_set_header        X-Forwarded-For $proxy_add_x_forwarded_for;
    proxy_set_header        X-Forwarded-Proto $scheme;
    proxy_set_header X-HTTPS-Protocol $ssl_protocol;
    proxy_set_header X-NginX-Proxy true;

    location / {
        proxy_pass http://127.0.0.1:9092;
    }

    return 404;
}