added docker UCS setup using appcenter join script

doc/rpm-build/debian.postinst

@@ -34,10 +34,17 @@ then
 	else
 		if grep -q '^DISTRIB_ID="*Univention"*$' /etc/lsb-release
 		then
+			if [ -n "$DOCKER_HOST_NAME" -a -n "$DB_HOST" ]
+			then
+				# docker UCS setup, use appcenter join script
+				:
+			else
+				# normal UCS setup
 				/usr/share/egroupware/doc/rpm-build/post_install.php \
 					--distro univention \
 					--admin_user "Administrator" \
 					--admin_passwd "*unchanged*" 2>&1 | /usr/bin/tee -a $install_log
+			fi
 		else
 			# Get configuration passwords
 			db_get "egroupware/header/user"
@@ -67,6 +74,7 @@ then
 				--admin_user "$admin_user" \
 				--admin_passwd "$admin_password" \
 				--lang "$lang" \
+				--db_type mysql \
 				--db_root "$db_root" \
 				--db_root_pw "$db_root_pw" 2>&1 | /usr/bin/tee -a $install_log
 		fi