Bug on clean Vultr Ubuntu 20.04 VPS

[draft1]

Attach the following commands output

• lsb_release -a :
  No LSB modules are available.
  Distributor ID: Ubuntu
  Description: Ubuntu 20.04.2 LTS
  Release: 20.04
  Codename: focal

• nginx -V :
  nginx version: nginx/1.21.0 (VirtuBox Nginx-ee)
  built by gcc 9.3.0 (Ubuntu 9.3.0-17ubuntu1~20.04)
  built with OpenSSL 1.1.1g 21 Apr 2020
  TLS SNI support enabled
  configure arguments: --with-cc-opt='-m64 -march=native -mtune=native -DTCP_FASTOPEN=23 -g -O3 -fstack-protector-strong -flto -ffat-lto-objects -fuse-ld=gold --param=ssp-buffer-size=4 -Wformat -Werror=format-security -Wimplicit-fallthrough=0 -fcode-hoisting -Wp,-D_FORTIFY_SOURCE=2 -gsplit-dwarf' --with-ld-opt='-lrt -ljemalloc -Wl,-z,relro -Wl,-z,now -fPIC -flto -ffat-lto-objects' --prefix=/usr/share --conf-path=/etc/nginx/nginx.conf --http-log-path=/var/log/nginx/access.log --error-log-path=/var/log/nginx/error.log --lock-path=/var/lock/nginx.lock --pid-path=/var/run/nginx.pid --http-client-body-temp-path=/var/lib/nginx/body --http-fastcgi-temp-path=/var/lib/nginx/fastcgi --http-proxy-temp-path=/var/lib/nginx/proxy --http-scgi-temp-path=/var/lib/nginx/scgi --http-uwsgi-temp-path=/var/lib/nginx/uwsgi --modules-path=/usr/share/nginx/modules --build='VirtuBox Nginx-ee' --with-file-aio --with-threads --with-http_v2_hpack_enc --with-http_v2_module --with-http_ssl_module --with-pcre-jit --with-http_stub_status_module --with-http_realip_module --with-http_auth_request_module --with-http_addition_module --with-http_gzip_static_module --with-http_gunzip_module --with-http_mp4_module --with-http_sub_module --with-compat --add-module=../ngx_http_substitutions_filter_module --add-dynamic-module=../srcache-nginx-module --add-dynamic-module=../ngx_http_redis --add-dynamic-module=../redis2-nginx-module --add-dynamic-module=../memc-nginx-module --add-module=../ngx_devel_kit --add-module=../set-misc-nginx-module --add-dynamic-module=../ngx_http_auth_pam_module --add-module=../nginx-module-vts --add-dynamic-module=../ipscrubtmp/ipscrub --add-module=../echo-nginx-module --add-module=../headers-more-nginx-module --add-module=../ngx_cache_purge --add-module=../ngx_brotli --with-zlib=../zlib-cf --with-openssl-opt='enable-ec_nistp_64_gcc_128 enable-tls1_3 no-ssl3-method -march=native -ljemalloc' --sbin-path=/usr/sbin/nginx

Describe the bug
nginx: [warn] the "http2_max_field_size" directive is obsolete, use the "large_client_header_buffers" directive instead in /etc/nginx/conf.d/tweaks.conf:4 nginx: [warn] the "http2_max_header_size" directive is obsolete, use the "large_client_header_buffers" directive instead in /etc/nginx/conf.d/tweaks.conf:5 nginx: [emerg] unknown "srcache_fetch_status" variable nginx: configuration file /etc/nginx/nginx.conf test failed