fix: remove secret as an installer question

src/install.js

@@ -22,11 +22,6 @@ questions.main = [
 		pattern: /^http(?:s)?:\/\//,
 		message: 'Base URL must begin with \'http://\' or \'https://\'',
 	},
-	{
-		name: 'secret',
-		description: 'Please enter a NodeBB secret',
-		default: nconf.get('secret') || utils.generateUUID(),
-	},
 	{
 		name: 'submitPluginUsage',
 		description: 'Would you like to submit anonymous plugin usage to nbbpm?',