hooks/conf_regen: Fix some shellcheck

hooks/conf_regen/03-ssh

@@ -18,9 +18,12 @@
 # along with this program. If not, see <http://www.gnu.org/licenses/>.
 #
 
-set -e
+# Exit hook on subcommand error or unset variable
+set -Eeuo pipefail
 
-. /usr/share/yunohost/helpers
+# Source YNH helpers
+# shellcheck source=../../helpers/helpers
+source /usr/share/yunohost/helpers
 
 do_pre_regen() {
     pending_dir=$1
@@ -34,7 +37,11 @@ do_pre_regen() {
     export ssh_keys=$(ls /etc/ssh/ssh_host_{ed25519,rsa,ecdsa}_key 2> /dev/null || true)
 
     # do not listen to IPv6 if unavailable
-    [[ -f /proc/net/if_inet6 ]] && ipv6_enabled=true || ipv6_enabled=false
+    if [[ -f /proc/net/if_inet6 ]]; then
+        ipv6_enabled=true
+    else
+        ipv6_enabled=false
+    fi
     export ipv6_enabled
 
     ynh_render_template "sshd_config" "${pending_dir}/etc/ssh/sshd_config"
@@ -44,6 +51,7 @@ do_post_regen() {
     regen_conf_files=$1
 
     # If no file changed, there's nothing to do
+
     [[ -n "$regen_conf_files" ]] || return 0
 
     # Enforce permissions for /etc/ssh/sshd_config
@@ -53,4 +61,4 @@ do_post_regen() {
     systemctl restart ssh
 }
 
-do_$1_regen ${@:2}
+"do_$1_regen" "${@:2}"