[ContextManager] Actually use the MemoryManger

Even though the MemoryManager is enabled for the ContextManager per
default, it never was actually used due a logic bug. Squash that bug!

emper/ContextManager.cpp

@@ -46,7 +46,7 @@ void ContextManager::putFreeContext(Context* context) {
 		context->recordStackUsage();
 	}
 
-	if constexpr (!emper::CONTEXT_MANAGER_WITH_MEMORY_MANAGER) {
+	if constexpr (emper::CONTEXT_MANAGER_WITH_MEMORY_MANAGER) {
 		putMemory(context);
 	} else {
 		delete context;