Invalid @context in Link header for PATCH Entity

[kzangeli]

Just spotted a functest that reveals a bug that I seem to have decided to ignore when TRoE was ignored:

troe_exhaustive_patch_attributes.test: Step 11

The Link header has a REGEX(.*), to let the bug stay alive ...

The @context in t he payload body is an array of ONE item:

  "@context": [ "https://raw.githubusercontent.com/FIWARE/tutorials.NGSI-LD/master/app/public/data-models/ngsi-context.jsonld" ],

If I make it a string instead, the test work just fine:

  "@context": "https://raw.githubusercontent.com/FIWARE/tutorials.NGSI-LD/master/app/public/data-models/ngsi-context.jsonld",