fixed ref in 2.4.1-maintenance

src/SOL002/VNFPerformanceManagement/definitions/VNFPerformanceManagement_def.yaml

@@ -51,7 +51,7 @@ definitions:
                   Measurement:      vCPU_utilization
                   Sub-counters:     vCPU utilization of each of the vCPUs of VnfcInstance1
                                     (vCPU_utilization.vCPU1, vCPU_utilization.vCPU2, etc.).
-              $ref: "SOL002SOL003_def.yaml#/definitions/IdentifierInVnf"
+              $ref: "../../../definitions/SOL002SOL003_def.yaml#/definitions/IdentifierInVnf"
             performanceMetric:
               description: >
                 Name of the metric collected.