fix: make header user agent filter compatible with WP

Author: girishpanchal30

includes/abstract/feedzy-rss-feeds-admin-abstract.php

@@ -860,7 +860,7 @@ private function init_feed( $feed_url, $cache, $sc, $allow_https = FEEDZY_ALLOW_
 
 		$feed->set_file_class( 'WP_SimplePie_File' );
 		$default_agent = $this->get_default_user_agent( $feed_url );
-		$feed->set_useragent( apply_filters( 'http_headers_useragent', $default_agent ) );
+		$feed->set_useragent( apply_filters( 'http_headers_useragent', $default_agent, is_array( $feed_url ) ? reset( $feed_url ) : $feed_url ) );
 		if ( false === apply_filters( 'feedzy_disable_db_cache', false, $feed_url ) ) {
 			SimplePie_Cache::register( 'wp_transient', 'WP_Feed_Cache_Transient' );
 			$feed->set_cache_location( 'wp_transient' );
@@ -917,7 +917,7 @@ function ( $time ) use ( $cache_time ) {
 		if ( isset( $_SERVER['HTTP_USER_AGENT'] ) ) {
 			// phpcs:ignore WordPressVIPMinimum.Variables.RestrictedVariables.cache_constraints___SERVER__HTTP_USER_AGENT__
 			$set_server_agent = sanitize_text_field( wp_unslash( $_SERVER['HTTP_USER_AGENT'] ) . SIMPLEPIE_USERAGENT );
-			$feed->set_useragent( apply_filters( 'http_headers_useragent', $set_server_agent ) );
+			$feed->set_useragent( apply_filters( 'http_headers_useragent', $set_server_agent, is_array( $feed_url ) ? reset( $feed_url ) : $feed_url ) );
 		}
 
 		$feed->init();