updated common-schema.json

We have noticed an error in the description of the attribute location in the file common-schema.json, a file that is embedded in most of the data models. It does not affect the data types (so the validation of the schemas is not affected) but it affects the qualification of the NGSI type that it is not properly identified,

GeoProperty is written with capital middle P.

The file has been updated and soon it will be launched an update of all the data models affected.