Fix Windows crash_generation_server for debug builds without -D_DEBUG

src/client/windows/crash_generation/crash_generation_server.cc

Index: src/client/windows/crash_generation/crash_generation_server.cc
diff --git a/src/client/windows/crash_generation/crash_generation_server.cc b/src/client/windows/crash_generation/crash_generation_server.cc
index 2c4f072c3119cccc63cab23fd3ba6542d154db42..bb0968fe01af946369ab2fd2079fb63af0c0c71a 100644
--- a/src/client/windows/crash_generation/crash_generation_server.cc
+++ b/src/client/windows/crash_generation/crash_generation_server.cc
@@ -85,7 +85,7 @@ static bool IsClientRequestValid(const ProtocolMessage& msg) {
           msg.assert_info != NULL);
 }
 
-#ifdef _DEBUG
+#ifndef NDEBUG
 static bool CheckForIOIncomplete(bool success) {
   // We should never get an I/O incomplete since we should not execute this
   // unless the operation has finished and the overlapped event is signaled. If