Do not try to clear a non existent request

library/src/main/java/com/bumptech/glide/request/RequestFutureTarget.java

@@ -220,8 +220,10 @@ public class RequestFutureTarget<T, R> implements FutureTarget<R>, Runnable {
      */
     @Override
     public void run() {
+        if (request != null) {
             request.clear();
         }
+    }
 
     /**
      * Can be safely called from either the main thread or a background thread to cleanup the resources used by this