Legend for required fields in configuration form

src/utils/modeHandler.js

@@ -93,14 +93,17 @@ export class Modal extends Component {
         if (config && 'displayMode' in config) {
             if (config.configurable && config.displayMode === "settings") {
                 return [
-                <Form
-                    className = "container"
-                    schema={this.modes.settingsSchema}
-                    onSubmit={this.handleSettingsChange.bind(this)}
-                    formData={config}
-                    liveValidate={true} />,
-                <br/>,
-                <p className="container"><span clasName="required">*</span> : required field</p>];
+                    <Form
+                        key="form"
+                        className = "container"
+                        schema={this.modes.settingsSchema}
+                        onSubmit={this.handleSettingsChange.bind(this)}
+                        formData={config}
+                        liveValidate={true} />,
+                    <br key="line-break"/>,
+                    <p className="container" key="required-field">
+                        <span clasName="required">*</span> : required field
+                    </p>];
             }
             if (config.hasReadme && config.displayMode === "readme") {
                 return this.modes.readme;