hi can you add Http for your SVM, i dont see that added for SVM and that why SDW not able to connect to http/Https.
example to enable http for svm:
mva-fas8080-::*> security login create -user-or-group-name snapcenter -application http -authentication-method password -role vsadmin -vserver SVM-name
once add the http for SVM try the adding svm to SDW.
thanks