Merge branch 'fix-8' into 'master'

An event cannot have a sensor, it is something intangible.

See merge request stf/stf-566/saref4wear!22

ontology/saref4wear.ttl

@@ -604,10 +604,6 @@ s4city:Event rdf:type owl:Class ;
              rdfs:subClassOf [ rdf:type owl:Restriction ;
                                owl:onProperty s4city:takesPlaceAtFacility ;
                                owl:allValuesFrom s4city:Facility
-                             ] ,
-                             [ rdf:type owl:Restriction ;
-                               owl:onProperty s4wear:hasSensor ;
-                               owl:allValuesFrom saref:Sensor
                              ] ;
              rdfs:isDefinedBy s4city: ;
              rdfs:label "Event"@en .