gistfile1.txt

    location ~ \+f/ { 
        try_files $uri @proxy_to_app;
    }
    location ~ \+doc/ {     
        try_files $uri @proxy_to_app;
    }   
    location / {
        proxy_pass http://localhost:3141;
        proxy_set_header  X-outside-url $scheme://$host;
        proxy_set_header  X-Real-IP $remote_addr;
    }   
    location @proxy_to_app {
        proxy_pass http://localhost:3141;
        proxy_set_header  X-outside-url $scheme://$host;
        proxy_set_header  X-Real-IP $remote_addr;
    }  

revised (only one repetition left):

location ~ \+(f|doc)/ {
    try_files $uri @proxy_to_app;
}
location / {
    proxy_pass http://localhost:3141;
    proxy_set_header  X-outside-url $scheme://$host;
    proxy_set_header  X-Real-IP $remote_addr;
}   
location @proxy_to_app {
    proxy_pass http://localhost:3141;
    proxy_set_header  X-outside-url $scheme://$host;
    proxy_set_header  X-Real-IP $remote_addr;
}