fix broken user check

debian/ai-auditd.postinst

@@ -4,10 +4,8 @@
 case "$1" in
 configure)
 
-        if ! getent user ai-auditd >/dev/null; then
-        	adduser --system --home /var/lib/auditd --no-create-home \
+       	adduser --quiet --system --home /var/lib/auditd --no-create-home \
 		--disabled-password ai-auditd
-	fi
 
 	mkdir -p /var/lib/auditd
 	chown -R ai-auditd:root /var/lib/auditd

debian/localauditd.postinst

@@ -4,14 +4,10 @@
 case "$1" in
 configure)
 
-	if ! getent group audit >/dev/null; then
-		addgroup --system audit
-	fi
+	addgroup --quiet --system audit
 
-        if ! getent user localaudit >/dev/null; then
-		adduser --system --home /var/spool/audit --no-create-home \
+	adduser --quiet --system --home /var/spool/audit --no-create-home \
 		--disabled-password --ingroup audit localaudit
-	fi
 
 	mkdir -p /var/spool/audit/incoming
 	chown -R localaudit:audit /var/spool/audit