fix: regression caused by 94b79ce402

`./nodebb setup` was no longer able to be called without arguments or env vars

src/install.js

@@ -47,7 +47,7 @@ questions.optional = [
 ];
 
 function checkSetupFlagEnv() {
-	let setupVal = install.values || {};
+	let setupVal = install.values;
 
 	const envConfMap = {
 		NODEBB_URL: 'url',
@@ -65,7 +65,10 @@ function checkSetupFlagEnv() {
 	};
 
 	// Set setup values from env vars (if set)
+	const envKeys = Object.keys(process.env);
+	if (Object.keys(envConfMap).some(key => envKeys.includes(key))) {
 		winston.info('[install/checkSetupFlagEnv] checking env vars for setup info...');
+		setupVal = setupVal || {};
 
 		Object.entries(process.env).forEach(([evName, evValue]) => { // get setup values from env
 			if (evName.startsWith('NODEBB_DB_')) {
@@ -76,6 +79,7 @@ function checkSetupFlagEnv() {
 		});
 
 		setupVal['admin:password:confirm'] = setupVal['admin:password'];
+	}
 
 	// try to get setup values from json, if successful this overwrites all values set by env
 	// TODO: better behaviour would be to support overrides per value, i.e. in order of priority (generic pattern):