Fix linux build issues with demo actor

[phil-vela]

When doing a linux server build I was getting some issues like:

In file included from /home/ubuntu/workspace/feature-net-imgui/vire/Plugins/UnrealNetImgui/Intermediate/Build/Linux/B4D820EA/UnrealEditor/Development/NetImgui/Module.NetImgui.11_of_11.cpp:9:
/home/ubuntu/workspace/feature-net-imgui/vire/Plugins/UnrealNetImgui/Source/Sample/NetImguiDemoActor.cpp:139:41: error: format string is not a string literal (potentially insecure) [-Werror,-Wformat-security]
                                ImGui::TextColored(kColorHighlight, TCHAR_TO_UTF8(*titleKenney));
                                                                    ^~~~~~~~~~~~~~~~~~~~~~~~~~~
/home/ubuntu/UnrealEngine/Engine/Source/Runtime/Core/Public/Containers/StringConv.h:970:28: note: expanded from macro 'TCHAR_TO_UTF8'
#define TCHAR_TO_UTF8(str) (ANSICHAR*)FTCHARToUTF8((const TCHAR*)str).Get()
                           ^          ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/home/ubuntu/workspace/feature-net-imgui/vire/Plugins/UnrealNetImgui/Source/Sample/NetImguiDemoActor.cpp:139:41: note: treat the string as an argument to avoid this
                                ImGui::TextColored(kColorHighlight, TCHAR_TO_UTF8(*titleKenney));
                                                                    ^
                                                                    "%s",
/home/ubuntu/UnrealEngine/Engine/Source/Runtime/Core/Public/Containers/StringConv.h:970:28: note: expanded from macro 'TCHAR_TO_UTF8'
#define TCHAR_TO_UTF8(str) (ANSICHAR*)FTCHARToUTF8((const TCHAR*)str).Get()

and

In file included from /home/ubuntu/workspace/feature-net-imgui/vire/Plugins/UnrealNetImgui/Intermediate/Build/Linux/B4D820EA/UnrealEditor/Development/NetImgui/Module.NetImgui.11_of_11.cpp:9:
/home/ubuntu/workspace/feature-net-imgui/vire/Plugins/UnrealNetImgui/Source/Sample/NetImguiDemoActor.cpp:294:80: error: conversion from 'size_t' (aka 'unsigned long') to 'const FStringFormatArg' is ambiguous
                        FString windowName = FString::Format(TEXT("NetImguiDemoActor Tick###{0}"), {reinterpret_cast<size_t>(this)}); // '###+IntegerID' Generates a unique Window ID so each actor have their own window
                                                                                                    ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Seems like it's just some default compiler args that don't appear on windows builds, this PR resolves

[sammyfreg]

This is actually caused by a safety warning, telling you to use the string format function with a literal string, instead of dynamic string that could introduce memory injection hacking.

[sammyfreg]

Looks good. Could you change this pull request to the dev branch instead?
Thank you.

[phil-vela]

Looks good. Could you change this pull request to the dev branch instead?
Thank you.

I’m accidentally pulling in some other commits so will remake - thanks for taking a look!