Be more explicit about SSO requirement

client/go/internal/cli/cmd/login.go

@@ -74,9 +74,8 @@ This command runs a browser-based authentication flow for the Vespa Cloud contro
 			if err != nil {
 				switch err.Error() {
 				case "600":
-					return errHint(fmt.Errorf("Unable to login through social channels"),
-						"Your organization does not allow logging in through our social channels",
-						"Please login by entering your address into the email field")
+					return errHint(fmt.Errorf("Your organization require SSO for Vespa Cloud access"),
+						"Please login by entering your email in the email address field")
 				default:
 					return fmt.Errorf("login error: %w", err)
 				}