Call getResponseBody0 before allocating the array.

Author: rlubke

providers/grizzly/src/main/java/org/asynchttpclient/providers/grizzly/GrizzlyResponse.java

@@ -107,6 +107,7 @@ public String getResponseBody(String charset) throws IOException {
      */
     @Override
     public byte[] getResponseBodyAsBytes() throws IOException {
+        final Buffer responseBody = getResponseBody0();
         final byte[] responseBodyBytes = new byte[responseBody.remaining()];
         final int origPos = responseBody.position();
         responseBody.get(responseBodyBytes);