Check that navigator is defined

lib/utils.js

@@ -169,7 +169,6 @@ function trim(str) {
  *
  * This allows axios to run in a web worker, and react-native.
  * Both environments support XMLHttpRequest, but not fully standard globals.
- * As of react-native 0.13, it can be identified from navigator.product.
  *
  * web workers:
  *  typeof window -> undefined
@@ -179,7 +178,7 @@ function trim(str) {
  *  navigator.product -> 'ReactNative'
  */
 function isStandardBrowserEnv() {
-  if (typeof navigator.product !== 'undefined' && navigator.product === 'ReactNative') {
+  if (typeof navigator !== 'undefined' && navigator.product === 'ReactNative') {
     return false;
   }
   return (