AppManager: Clean up VPN node and auth keys upon app removal

Change-Id: Ie76278556247d16806ba81286621adca973e3f6e
diff --git a/core/installer/derived.go b/core/installer/derived.go
index 508cd3e..d99f02b 100644
--- a/core/installer/derived.go
+++ b/core/installer/derived.go
@@ -69,7 +69,7 @@
 	values any,
 	schema Schema,
 	networks []Network,
-	vpnKeyGen VPNAuthKeyGenerator,
+	vpnKeyGen VPNAPIClient,
 ) (map[string]any, error) {
 	ret := make(map[string]any)
 	for _, f := range schema.Fields() {
@@ -100,7 +100,7 @@
 						return nil, fmt.Errorf("could not resolve username: %+v %s %+v", def.Meta(), v, root)
 					}
 				}
-				authKey, err := vpnKeyGen.Generate(username)
+				authKey, err := vpnKeyGen.GenerateAuthKey(username)
 				if err != nil {
 					return nil, err
 				}