Properly initialize AsyncHttpClientConfigBean.ioThreadMultiplier

Otherwise, Netty provider will crash as worker count will be 0

Author: Stephane Landelle

src/main/java/com/ning/http/client/AsyncHttpClientConfigBean.java

@@ -54,6 +54,7 @@ void configureDefaults() {
         maxDefaultRedirects = Integer.getInteger(ASYNC_CLIENT + "defaultMaxRedirects", 5);
         compressionEnabled = Boolean.getBoolean(ASYNC_CLIENT + "compressionEnabled");
         userAgent = System.getProperty(ASYNC_CLIENT + "userAgent", "NING/1.0");
+        ioThreadMultiplier = Integer.getInteger(ASYNC_CLIENT + "ioThreadMultiplier", 8);
 
         boolean useProxySelector = Boolean.getBoolean(ASYNC_CLIENT + "useProxySelector");
         boolean useProxyProperties = Boolean.getBoolean(ASYNC_CLIENT + "useProxyProperties");