Fix authentication example (#4145)

examples/fullstack-auth/Cargo.toml

@@ -48,7 +48,7 @@ optional = true
 [features]
 default = []
 server = [
-    "dioxus-fullstack/server",
+    "dioxus/server",
     "dep:dioxus-cli-config",
     "dep:axum",
     "dep:tokio",