fix #411 : add label

src/main/resources/fess_indices/fess/doc.json

@@ -505,6 +505,10 @@
         "type": "string",
         "index": "not_analyzed"
       },
+      "label": {
+        "type": "string",
+        "index": "not_analyzed"
+      },
       "segment": {
         "type": "string",
         "index": "not_analyzed"