try to correct di-dist arg

mirror/syncubuntu.sh

@@ -18,6 +18,10 @@ fi
 
 DONE=0
 
+DIDIST="$(
+    echo "$UBUNTU_MIRROR_PROJECTS" | tr "," "\n" | grep -v "\-" | tr "\n" ","
+)"
+
 while [[ $DONE -eq 0 ]]; do
     debmirror \
         -a ${UBUNTU_MIRROR_ARCHITECTURES} \
@@ -25,7 +29,7 @@ while [[ $DONE -eq 0 ]]; do
         -h ${UBUNTU_MIRROR_UPSTREAM} \
         -d ${UBUNTU_MIRROR_PROJECTS} \
         $SOURCEOPT \
-        --di-dist=dists \
+        --di-dist="$DIDIST" \
         --di-arch=arches \
         --ignore-small-errors \
         -r /ubuntu \