无法安装pure_ftpd，和ssr有冲突

1、debian 7 vps
我先安装的ssr，再安装lnmp，则ssr无法使用，我重新给ssr的锻炼设置iptabls才可以
 
2、一键安装中无法安装ftp，我先安装的其他组件，再单独安装ftp也一样，报错，见倒数后6行，麻烦帮忙看看如何解决
fs.file-max = 65535
fs.inotify.max_user_instances = 8192
net.ipv4.tcp_syncookies = 1
net.ipv4.tcp_fin_timeout = 30
net.ipv4.tcp_tw_reuse = 1
net.ipv4.ip_local_port_range = 1024 65000
net.ipv4.tcp_max_syn_backlog = 65536
net.ipv4.tcp_max_tw_buckets = 6000
net.ipv4.route.gc_timeout = 100
net.ipv4.tcp_syn_retries = 1
net.ipv4.tcp_synack_retries = 1
net.core.somaxconn = 65535
net.core.netdev_max_backlog = 262144
net.ipv4.tcp_timestamps = 0
net.ipv4.tcp_max_orphans = 262144
23 Feb 16:36:11 ntpdate[30385]: adjust time server 104.232.3.3 offset 0.000804 sec
Stopping enhanced syslogd: rsyslogd.
Starting enhanced syslogd: rsyslogd.
Restarting OpenBSD Secure Shell server: sshd.
~/lnmp/src ~/lnmp
Download pureftpd...
--2017-02-23 16:36:11-- https://download.pureftpd.org/pub/pure-ftpd/releases/pure-ftpd-1.0.45.tar.gz
Resolving download.pureftpd.org (download.pureftpd.org)... 37.59.238.213
Connecting to download.pureftpd.org (download.pureftpd.org)|37.59.238.213|:443... connected.
GnuTLS: A TLS fatal alert has been received.
Unable to establish SSL connection.
pure-ftpd-1.0.45.tar.gz download failed, Please contact the author!
Killed
~/lnmp