Remove include experimental/filesystem

This include is no longer needed.

Tested: bmcweb built.

Change-Id: Id754779cc8340678f03b8841abee807c90b959ff
Signed-off-by: Gunnar Mills <gmills@us.ibm.com>
diff --git a/include/nbd_proxy.hpp b/include/nbd_proxy.hpp
index 4a9cfb8..0356161 100644
--- a/include/nbd_proxy.hpp
+++ b/include/nbd_proxy.hpp
@@ -25,7 +25,6 @@
 #include <privileges.hpp>
 #include <webserver_common.hpp>
 
-#include <experimental/filesystem>
 #include <variant>
 
 namespace crow