update readme, fix some bugs

mirror/syncubuntu.sh

@@ -12,16 +12,16 @@ mkdir -p "$DST/ubuntu"
 export GNUPGHOME="/etc/debmirror/ubuntu"
 
 SOURCEOPT="--nosource"
-if [[ ! -z "$UBUNTU_SOURCE_MIRROR" ]]; then
+if [[  "$UBUNTU_ENABLE_SOURCE_MIRRORING" != "false" ]]; then
     SOURCEOPT="--source"
 fi
 
 debmirror \
-	-a ${MIRROR_ARCHITECTURES} \
-	$SOURCEOPT \
-	-s ${MIRROR_CATEGORIES} \
-	-h ${UBUNTU_MIRROR_SOURCE} \
+	-a ${UBUNTU_MIRROR_ARCHITECTURES} \
+	-s ${UBUNTU_MIRROR_CATEGORIES} \
+	-h ${UBUNTU_MIRROR_UPSTREAM} \
 	-d ${UBUNTU_MIRROR_PROJECTS} \
+	$SOURCEOPT \
     --ignore-small-errors \
 	-r /ubuntu \
     --getcontents \