Fix IPv6 handling in ssh regen conf script

data/hooks/conf_regen/03-ssh

@@ -11,9 +11,9 @@ do_pre_regen() {
 
   # Don't overwrite configuration if from_script
   if [[ ! -f /etc/yunohost/from_script ]]; then
+
       # do not listen to IPv6 if unavailable
-      [[ -f /proc/net/if_inet6 ]] \
-        || sed -i "s/ListenAddress ::/#ListenAddress ::/g" sshd_config
+      [[ -f /proc/net/if_inet6 ]] && ipv6_enabled=true || ipv6_enabled=false
 
       ssh_keys=$(ls /etc/ssh/ssh_host_{ed25519,rsa,ecdsa}_key 2>/dev/null)
 
@@ -23,6 +23,7 @@ do_pre_regen() {
       fi
 
       export ssh_keys
+      export ipv6_enabled
       ynh_render_template "sshd_config" "${pending_dir}/etc/ssh/sshd_config"
   fi
 }

data/templates/ssh/sshd_config

@@ -4,7 +4,7 @@
 Protocol 2
 Port 22
 
-ListenAddress ::
+{% if ipv6_enabled == "true" %}ListenAddress ::{% endif %}
 ListenAddress 0.0.0.0
 
 {% for key in ssh_keys.split() %}