Fix a few property warnings on Globals access

Hand-picked from 515f92d03b6bb4e8a42d5b88d603c96c69d233a4.

editor/editor_node.cpp

@@ -6313,7 +6313,10 @@ EditorNode::EditorNode() {
 	{
 
 		_initializing_addons = true;
-		Vector<String> addons = Globals::get_singleton()->get("editor_plugins/enabled");
+		Vector<String> addons;
+		if (Globals::get_singleton()->has("editor_plugins/enabled")) {
+			addons = Globals::get_singleton()->get("editor_plugins/enabled");
+		}
 
 		for (int i = 0; i < addons.size(); i++) {
 			set_addon_plugin_enabled(addons[i], true);

editor/editor_settings.cpp

@@ -412,7 +412,7 @@ void EditorSettings::setup_network() {
 	IP::get_singleton()->get_local_addresses(&local_ip);
 	String lip;
 	String hint;
-	String current = get("network/debug_host");
+	String current = has("network/debug_host") ? get("network/debug_host") : "";
 	int port = has("network/debug_port") ? (int)get("network/debug_port") : 6007;
 
 	for (List<IP_Address>::Element *E = local_ip.front(); E; E = E->next()) {

main/main.cpp

@@ -672,7 +672,7 @@ Error Main::setup(const char *execpath, int argc, char *argv[], bool p_second_ph
 		video_mode.width = globals->get("display/width");
 	if (!force_res && use_custom_res && globals->has("display/height"))
 		video_mode.height = globals->get("display/height");
-	if (!editor && (!bool(globals->get("display/allow_hidpi")) || force_lowdpi)) {
+	if (!editor && ((globals->has("display/allow_hidpi") && !globals->get("display/allow_hidpi")) || force_lowdpi)) {
 		OS::get_singleton()->_allow_hidpi = false;
 	}
 	if (use_custom_res && globals->has("display/fullscreen"))