Fix API crash due to model changes

Signed-off-by: Tushar Goel <tushar.goel.dav@gmail.com>

Author: TG1999

vulnerabilities/api.py

@@ -43,7 +43,7 @@ class Meta:
 
 
 class VulnerabilityReferenceSerializer(serializers.ModelSerializer):
-    scores = VulnerabilitySeveritySerializer(many=True)
+    scores = VulnerabilitySeveritySerializer(many=True, source="vulnerabilityseverity_set")
 
     class Meta:
         model = VulnerabilityReference