[minor] Packing Slip get_query
diff --git a/erpnext/stock/doctype/packing_slip/packing_slip.py b/erpnext/stock/doctype/packing_slip/packing_slip.py
index bd79835..1916cef 100644
--- a/erpnext/stock/doctype/packing_slip/packing_slip.py
+++ b/erpnext/stock/doctype/packing_slip/packing_slip.py
@@ -166,4 +166,4 @@
and %s like "%s" %s
limit %s, %s """ % ("%s", searchfield, "%s",
get_match_cond(doctype), "%s", "%s"),
- (filters["delivery_note"], "%%%s%%" % txt, start, page_len))
+ ((filters or {}).get("delivery_note"), "%%%s%%" % txt, start, page_len))