Changed the operator for "not_match"

lib/util/search.js

@@ -340,9 +340,11 @@ SearchClient.prototype.appendCriteriaForKeywordContains = function(query, keywor
 
   var appendMultiMatchQuery = function(query, type, keywords) {
     var target;
+    var operator = 'and';
     switch (type) {
       case 'not_match':
         target = query.body.query.bool.must_not;
+        operator = 'or';
         break;
       case 'match':
       default:
@@ -359,7 +361,7 @@ SearchClient.prototype.appendCriteriaForKeywordContains = function(query, keywor
           // "path_en",
           // "body_en",
         ],
-        operator: "and"
+        operator: operator,
       }
     });