Do not reverse bytes for nullvm

more changes:
- removed unnecessary #include from test/null_vm_test.cc

Fixes proxy-wasm#294

Signed-off-by: Konstantin Maksimov <[email protected]>

Author: knm3000

test/null_vm_test.cc

@@ -16,7 +16,6 @@
 
 #include "include/proxy-wasm/null.h"
 #include "include/proxy-wasm/null_vm_plugin.h"
-#include "include/proxy-wasm/pairs_util.h"
 
 #include "gtest/gtest.h"