fix(db_query): Add fallback value irrespective of operator

frappe/model/db_query.py

@@ -492,7 +492,7 @@ class DatabaseQuery(object):
 				f.value = date_range
 				fallback = "'0001-01-01 00:00:00'"
 
-			if f.operator in ('>', '<') and (f.fieldname in ('creation', 'modified')):
+			if (f.fieldname in ('creation', 'modified')):
 				value = cstr(f.value)
 				fallback = "NULL"