ngnix 1.9.14
php-fpm
Ubuntu

конфиг
server { listen 80; server_name domain.com *.domain.com www.domain.com; return 301 https://$host$request_uri; } server { listen 443; server_name domain.com *.domain.com www.domain.com; charset UTF-8; disable_symlinks if_not_owner from=$root_path; index index.php; root $root_path/$subdomain; set $root_path /var/www/user_name/data/www; set $subdomain domain.com; if ($host ~* ^((.*).domain.com)$) { set $subdomain $1; } access_log /var/www/httpd-logs/domain.com.access.log; error_log /var/www/httpd-logs/domain.com.error.log notice; include /etc/nginx/vhosts-includes/*.conf; location / { location ~ [^/]\.ph(p\d*|tml)$ { try_files /does_not_exists @php; } try_files $uri $uri/ /index.php?q=$request_uri; } location @php { fastcgi_index index.php; fastcgi_param PHP_ADMIN_VALUE «sendmail_path = /usr/sbin/sendmail -t -i -f webmaster@domain.com»; fastcgi_pass unix:/var/www/php-fpm/user_name.sock; fastcgi_split_path_info ^((?U).+\.ph(?:p\d*|tml))(/?.+)$; try_files $uri =404; include fastcgi_params; } ssi on; add_header Strict-Transport-Security «max-age=31536000;»; ssl on; ssl_certificate "/var/www/httpd-cert/user_name/domain.com.crtca"; ssl_certificate_key "/var/www/httpd-cert/user_name/domain.com.key"; ssl_ciphers HIGH:!RC4:!aNULL:!eNULL:!MD5:!EXPORT:!EXP:!LOW:!SEED:!CAMELLIA:!IDEA:!PSK:!SRP:!SSLv2; ssl_prefer_server_ciphers on; ssl_protocols TLSv1 TLSv1.1 TLSv1.2; }

пытюсь включить http/2
меняю listen 443 на listen 443 ssl http2
сервер падает с ошибкой [emerg] 1466#1466: bind() to 0.0.0.0:443 failed (98: Address already in use)
В чем может быть дело?

netstat -nlpt возвращает следующее
Active Internet connections (only servers) Proto Recv-Q Send-Q Local Address Foreign Address State PID/Program name tcp 0 0 0.0.0.0:22 0.0.0.0:* LISTEN 504/sshd tcp 0 0 0.0.0.0:25 0.0.0.0:* LISTEN 863/exim4 tcp 0 0 0.0.0.0:443 0.0.0.0:* LISTEN 912/nginx.conf tcp 0 0 100.100.100.100:1500 0.0.0.0:* LISTEN 908/ihttpd accept tcp 0 0 0.0.0.0:993 0.0.0.0:* LISTEN 511/dovecot tcp 0 0 0.0.0.0:995 0.0.0.0:* LISTEN 511/dovecot tcp 0 0 127.0.0.1:3306 0.0.0.0:* LISTEN 587/mysqld tcp 0 0 0.0.0.0:587 0.0.0.0:* LISTEN 863/exim4 tcp 0 0 0.0.0.0:110 0.0.0.0:* LISTEN 511/dovecot tcp 0 0 0.0.0.0:143 0.0.0.0:* LISTEN 511/dovecot tcp 0 0 0.0.0.0:80 0.0.0.0:* LISTEN 912/nginx.conf tcp 0 0 0.0.0.0:465 0.0.0.0:* LISTEN 863/exim4 tcp6 0 0 :::22 :::* LISTEN 504/sshd tcp6 0 0 :::25 :::* LISTEN 863/exim4 tcp6 0 0 :::587 :::* LISTEN 863/exim4 tcp6 0 0 :::465 :::* LISTEN 863/exim4 tcp6 0 0 :::21 :::* LISTEN 983/proftpd: (accep