Update: Minor changes

Author: Nodonisko

README.md

@@ -229,5 +229,5 @@ this.cache.disableCache(true);
 If you want disable "don't invalidate" when device is offline, you can do it simply.
 
 ```js
-this.cache.setOfflineInvalidate(true);
+this.cache.setOfflineInvalidate(false);
 ```

src/cache.service.ts

@@ -73,7 +73,7 @@ export class CacheService {
    * @param {boolean} offlineInvalidate
    */
   public setOfflineInvalidate(offlineInvalidate: boolean) {
-    this.invalidateOffline = offlineInvalidate;
+    this.invalidateOffline = !offlineInvalidate;
   }
 
   /**