[Context] Fix DBG message

The thread local currentContext was already set to nullptr when we
logged it. Use the right field instead.

emper/Context.cpp

@@ -27,6 +27,7 @@ auto operator<<(std::ostream& strm, const Context& context) -> std::ostream& {
 	// Can't use new context hook to communicate the context to free.
 	lastContextBeforeReturningToOriginalStack = currentContext;
 	currentContext = nullptr;
-	DBG("Switchting to original stack " << &originalStack << " from " << currentContext);
+	DBG("Switchting to original stack " << &originalStack << " from "
+																			<< lastContextBeforeReturningToOriginalStack);
 	switch_and_load_context(&originalStack);
 }