fix null ref error

Author: lucashuet93

src/APIM_ARMTemplate/apimtemplate/Extractor/EntityExtractors/BackendExtractor.cs

@@ -89,7 +89,9 @@ public bool DoesPolicyReferenceBackend(string policyContent, IEnumerable<Templat
         {
             // a policy is referenced by a backend with the set-backend-service policy, which will reference use the backends name or url, or through referencing a named value that applies to the backend
             var namedValueResourcesUsedByBackend = namedValueResources.Where(resource => DoesBackendReferenceNamedValue(resource, backendTemplateResource));
-            if (policyContent.Contains(backendName) || policyContent.Contains(backendTemplateResource.properties.url) || policyContent.Contains(backendTemplateResource.properties.resourceId))
+            if ((backendName != null && policyContent.Contains(backendName)) || 
+                (backendTemplateResource.properties.url != null && policyContent.Contains(backendTemplateResource.properties.url)) || 
+                (backendTemplateResource.properties.resourceId != null && policyContent.Contains(backendTemplateResource.properties.resourceId)))
             {
                 return true;
             }

src/APIM_ARMTemplate/apimtemplate/Properties/launchSettings.json

@@ -2,7 +2,7 @@
   "profiles": {
     "apimtemplate": {
       "commandName": "Project",
-      "commandLineArgs": "extract  --name apiphany --resourceGroup vlvinogr-apim --fileFolder C:\\\\\\\\Users\\\\\\\\lucashh\\\\\\\\Desktop\\\\\\\\Projects\\\\\\\\APIM-ARM\\\\\\\\ExtractedTemplates\\\\Full"
+      "commandLineArgs": "extract  --name LucasBlankLinked --resourceGroup LucasHuetHudsonInternal --fileFolder C:\\\\\\\\Users\\\\\\\\lucashh\\\\\\\\Desktop\\\\\\\\Projects\\\\\\\\APIM-ARM\\\\\\\\ExtractedTemplates\\\\SingleAPI --apiName firstAPI"
     }
   }
 }