Fix redundant forward declaration warning

Author: Megamouse

rpcs3/Emu/NP/rpcn_client.cpp

@@ -1,6 +1,6 @@
+#include "stdafx.h"
 #include "Emu/Cell/lv2/sys_net/sys_net_helpers.h"
 #include "Emu/NP/ip_address.h"
-#include "stdafx.h"
 #include <string>
 #include <mutex>
 #include <thread>
@@ -43,8 +43,6 @@
 
 LOG_CHANNEL(rpcn_log, "rpcn");
 
-int get_native_error();
-
 template <>
 void fmt_class_string<rpcn::ErrorType>::format(std::string& out, u64 arg)
 {