fix showtextbox requiring a parameter

src/gui/options/options.js

@@ -89,12 +89,12 @@ App.UI.OptionsGroup = (function() {
 		}
 
 		/**
-		 * @param {Object} params
+		 * @param {Object} [params]
 		 * @param {string} [params.unit]
 		 * @param {boolean} [params.large=false]
 		 * @returns {Option}
 		 */
-		showTextBox({unit, large = false}) {
+		showTextBox({unit, large = false} = {}) {
 			this.textbox = {unit: unit, large: large};
 			return this;
 		}