Fixed NullPointerException that may happen on timeout

Author: johanhaleby

rxjava-contrib/rxjava-apache-http/src/main/java/rx/apache/http/consumers/ResponseConsumerDelegate.java

@@ -93,7 +93,9 @@ protected HttpResponse buildResult(HttpContext context) throws Exception {
 
     @Override
     protected void releaseResources() {
-        consumer._releaseResources();
+        if (consumer != null) {
+            consumer._releaseResources();
+        }
     }
 
 }