Web: Fix editor build after #pragma once refactoring

[akien-mga]

#102298 inadvertently broke the web editor build (which we don't test on CI), due to this weird setup for WebToolsEditorPlugin:

#ifndef WEB_TOOLS_EDITOR_PLUGIN
#define WEB_TOOLS_EDITOR_PLUGIN

#include "core/io/zip_io.h"
#include "editor/plugins/editor_plugin.h"

class WebToolsEditorPlugin : public EditorPlugin {
	GDCLASS(WebToolsEditorPlugin, EditorPlugin);

private:
	void _download_zip();

public:
	static void initialize();

	WebToolsEditorPlugin();
};

#else

class WebToolsEditorPlugin {
public:
	static void initialize() {}
};

#endif

While replacing the header guard we missed the weird #else clause here.

This #else seems to be a bug after a past refactor, as the original class @Faless added in c54de7f actually had this condition: #if defined(TOOLS_ENABLED) && defined(JAVASCRIPT_ENABLED).

The condition was removed when refactoring how this file gets compiled via SCons so it's properly editor-only anyway, but the #else wasn't removed.

[Repiteo]

Beat me to the punch

[akien-mga]

For the record, we're merging this nominally for 4.5-dev2, but we're technically hotfixing the 4.5-dev1 source (based off 97241ff) with this to fix the web builds specifically. Other 4.5-dev1 builds are made from 97241ff.