Insertion of single concise array item is not reduced according to JSON-LD Rules

[jason-fox]

Insert an entity and retrieve it.

curl -L -X POST 'http://localhost:1026/ngsi-ld/v1/entities/' \
-H 'Content-Type: application/json' \
-H 'Link: <http://context/ngsi-context.jsonld>; rel="http://www.w3.org/ns/json-ld#context"; type="application/ld+json"' \
--data-raw '{
      "id": "urn:ngsi-ld:TemperatureSensor:001",
      "type": "TemperatureSensor",
      "category": ["sensor"]
      ,
      "temperature": {
          
            "value": 25,
            "unitCode": "CEL"
      }
}'

curl -L -X GET 'http://localhost:1026/ngsi-ld/v1/entities/urn:ngsi-ld:TemperatureSensor:001?options=sysAttrs' \
-H 'Link: <http://context/ngsi-context.jsonld>; rel="http://www.w3.org/ns/json-ld#context"; type="application/ld+json"'

category looks like this:

"category": {
        "type": "Property",
       "value": [
            "sensor"
        ]
    },

An array with one entry should be reduced to a single value since the @context of value doesn't state it is @set

[jason-fox]

Fixed and verified.