fix issues in unmount (android)

autoHeightWebView/index.android.js

     componentWillUnmount() {
         this.stopInterval();
         if (IsBelowKitKat) {
-            DeviceEventEmitter.removeListener("webViewBridgeMessage", listenWebViewBridgeMessage);
+            DeviceEventEmitter.removeListener("webViewBridgeMessage", this.listenWebViewBridgeMessage);
         }
     }
 

package.json

 {
   "name": "react-native-autoheightwebview",
-  "version": "0.0.14",
+  "version": "0.0.15",
   "description": "An auto height webview for React Native",
   "main": "autoHeightWebView",
   "files": ["android/", "autoHeightWebView/"],