Improve monitor shouldComponentUpdate

- did not tell apart 0 and -0
- would always re-render if value was NaN

src/containers/monitor.jsx

@@ -91,7 +91,8 @@ class Monitor extends React.Component {
         for (const key of Object.getOwnPropertyNames(nextProps)) {
             // Don't need to rerender when other monitors are moved.
             // monitorLayout is only used during initial layout.
-            if (key !== 'monitorLayout' && nextProps[key] !== this.props[key]) {
+            // Using Object.is to tell apart 0 and -0 and avoid unnecessary re-renders for NaN
+            if (key !== 'monitorLayout' && !Object.is(nextProps[key], this.props[key])) {
                 return true;
             }
         }