Work around for pointermove event on hidden map (#1450)

Author: Pessimistress

src/components/interactive-map.js

@@ -134,6 +134,10 @@ function normalizeEvent(event) {
   if (event.lngLat || !event.offsetCenter) {
     return event;
   }
+  // https://github.com/visgl/react-map-gl/issues/1449
+  if (!this.width || !this.height) {
+    return event;
+  }
 
   const {
     offsetCenter: {x, y}