Comma on strings and styling button

src/components/views/rooms/RoomSettings.js

@@ -947,7 +947,7 @@ module.exports = React.createClass({
             </AccessibleButton>;
         }
 
-        devtoolsButton = <AccessibleButton onClick={this._openDevtools}>
+        const devtoolsButton = <AccessibleButton className="mx_RoomSettings_devtoolsButton" onClick={this._openDevtools}>
             { _t("Open Devtools") }
         </AccessibleButton>;
 

src/i18n/strings/en_EN.json

@@ -1269,5 +1269,5 @@
     "Failed to set direct chat tag": "Failed to set direct chat tag",
     "Failed to remove tag %(tagName)s from room": "Failed to remove tag %(tagName)s from room",
     "Failed to add tag %(tagName)s to room": "Failed to add tag %(tagName)s to room",
-    "Open Devtools": "Open Devtools",
+    "Open Devtools": "Open Devtools"
 }