fix: check if get_current_screen is an object

Naprawa błędu który wypluwa jedna z wtyczek

Fatal error: Uncaught Error: Call to a member function is_block_editor() on null
in /var/www/html/wp-content/plugins/dropshipping-export/vendor_prefixed/wpdesk/wp-notice/src/WPDesk/Notice/Notice.php on line 86
Call stack:
DropshippingExportVendor\W\N\Notice::isBlockEditor()
wp-content/plugins/dropshipping-export/vendor_prefixed/wpdesk/wp-notice/src/WPDesk/Notice/Notice.php:176
DropshippingExportVendor\W\N\Notice::addGutenbergScript()
wp-includes/class-wp-hook.php:308
WP_Hook::apply_filters()
wp-includes/class-wp-hook.php:332
WP_Hook::do_action()
wp-includes/plugin.php:517
do_action()
wp-content/plugins/woocommerce-memberships/vendor/skyverge/wc-plugin-framework/woocommerce/admin/abstract-sv-wc-plugin-admin-setup-wizard.php:326
SkyVerge\W\P\v\A\Setup_Wizard::render_page()
wp-includes/class-wp-hook.php:308
WP_Hook::apply_filters()
wp-includes/class-wp-hook.php:332
WP_Hook::do_action()
wp-includes/plugin.php:517
do_action()
wp-admin/admin.php:175
require_once()
wp-admin/index.php:10

CHANGELOG.md

+## [3.2.3] - 2023-04-06
+### Fixed
+- fatal error if get_current_screen function return null
 ## [3.2.2] - 2023-03-03
 ### Added
 - security nonce in permanent dismissible notice ajax action