Bug fix: #887

Author: masashiGMS

src/android/plugin/google/maps/GoogleMaps.java

@@ -645,7 +645,9 @@ private Boolean getLicenseInfo(JSONArray args, CallbackContext callbackContext)
   }
 
   private void closeWindow() {
-    mapFrame.removeView(mapView);
+    if (mapView != null) {
+      mapFrame.removeView(mapView);
+    }
     if (mPluginLayout != null &&
         mapDivLayoutJSON != null) {
       mPluginLayout.attachMyView(mapView);