Disable UI if it's not compiled in. (#5773)

* Disable UI if it's not compiled in.

* Properly enabled/disable ui server depending on features.

Cargo.toml

@@ -72,13 +72,14 @@ daemonize = "0.2"
 [features]
 default = ["ui-precompiled"]
 ui = [
-	"dapps",
+	"ui-enabled",
 	"parity-dapps/ui",
 ]
 ui-precompiled = [
-	"dapps",
+	"ui-enabled",
 	"parity-dapps/ui-precompiled",
 ]
+ui-enabled = ["dapps"]
 dapps = ["parity-dapps"]
 ipc = ["ethcore/ipc", "ethsync/ipc"]
 jit = ["ethcore/jit"]

parity/configuration.rs

@@ -1036,7 +1036,7 @@ impl Configuration {
 			self.args.flag_geth ||
 			self.args.flag_no_ui;
 
-		!ui_disabled
+		!ui_disabled && cfg!(feature = "ui-enabled")
 	}
 
 	fn verifier_settings(&self) -> VerifierSettings {

parity/rpc.rs

@@ -102,7 +102,7 @@ impl From<UiConfiguration> for HttpConfiguration {
 impl Default for UiConfiguration {
 	fn default() -> Self {
 		UiConfiguration {
-			enabled: true,
+			enabled: true && cfg!(feature = "ui-enabled"),
 			port: 8180,
 			interface: "127.0.0.1".into(),
 			hosts: Some(vec![]),