SIG: Prevent PHP warning when setting key doesn't exist (#48873)

Author: tbradsha

projects/packages/publicize/changelog/fix-social-image-generator-php_warnings

@@ -0,0 +1,4 @@
+Significance: patch
+Type: fixed
+
+SIG: Prevent PHP warning when setting key doesn't exist. 

projects/packages/publicize/src/social-image-generator/class-setup.php

@@ -94,7 +94,7 @@ public function generate_token_on_save( $post_id, $post, $update ) {
 		if (
 			! $update &&
 			'auto-draft' === $post->post_status &&
-			$settings->get_settings()['socialImageGeneratorSettings']['enabled'] &&
+			! empty( $settings->get_settings()['socialImageGeneratorSettings']['enabled'] ) &&
 			empty( $post_settings->get_settings( true ) ) &&
 			'jetpack-social-note' !== $post->post_type
 		) {