Fixed Render[Texture|Window] crash when released while on use

Former-commit-id: 30b4bd5b7eb7b665cecfe6366117b7a3b4290202

src/Nazara/Renderer/RenderTexture.cpp

@@ -358,6 +358,9 @@ void NzRenderTexture::Destroy()
 {
 	if (m_impl)
 	{
+		if (IsActive())
+			NzRenderer::SetTarget(nullptr);
+
 		bool canFreeFBO = true;
 		#if NAZARA_RENDERER_SAFE
 		if (NzContext::GetCurrent() != m_impl->context)

src/Nazara/Renderer/RenderWindow.cpp

@@ -7,6 +7,7 @@
 #include <Nazara/Core/Thread.hpp>
 #include <Nazara/Renderer/Context.hpp>
 #include <Nazara/Renderer/OpenGL.hpp>
+#include <Nazara/Renderer/Renderer.hpp>
 #include <Nazara/Renderer/Texture.hpp>
 #include <stdexcept>
 #include <Nazara/Renderer/Debug.hpp>
@@ -318,6 +319,9 @@ void NzRenderWindow::OnWindowDestroy()
 {
 	if (m_context)
 	{
+		if (IsActive())
+			NzRenderer::SetTarget(nullptr);
+
 		delete m_context;
 		m_context = nullptr;
 	}