router: fix sed delimiter in detect_volatile_domains for names with /

router/route-update.sh

@@ -147,7 +147,7 @@ detect_volatile_domains()
 
     if [ -s "$volatile_file" ] ; then
         vlog "[$name]$label volatile domains (TTL≤${ttl_threshold}s, single A): $(wc -l < "$volatile_file")"
-        [ -n "$VERBOSE" ] && sed "s/^/  [$name]$label   /" "$volatile_file" >&2 || true
+        [ -n "$VERBOSE" ] && sed "s|^|  [$name]$label   |" "$volatile_file" >&2 || true
     fi
 }