THRIFT-2608 TNonblockingServer.cpp warnings on clang 3.4

Patch: Konrad Grochowski
diff --git a/lib/cpp/src/thrift/server/TNonblockingServer.cpp b/lib/cpp/src/thrift/server/TNonblockingServer.cpp
index 43cdc50..7bd42e2 100644
--- a/lib/cpp/src/thrift/server/TNonblockingServer.cpp
+++ b/lib/cpp/src/thrift/server/TNonblockingServer.cpp
@@ -156,12 +156,6 @@
   /// Count of the number of calls for use with getResizeBufferEveryN().
   int32_t callsForResize_;
 
-  /// Task handle
-  int taskHandle_;
-
-  /// Task event
-  struct event taskEvent_;
-
   /// Transport to read from
   boost::shared_ptr<TMemoryBuffer> inputTransport_;