Make sure the context passed to checkConnection is not null

Author: daniloercoli

WordPressUtils/src/main/java/org/wordpress/android/util/NetworkUtils.java

@@ -77,6 +77,9 @@ public static boolean isAirplaneModeOn(Context context) {
      * and returns false
      */
     public static boolean checkConnection(Context context) {
+        if(context == null) {
+            return false;
+        }
         if (isNetworkAvailable(context)) {
             return true;
         }