use coop png file instead of gif

Author: RistoNiinemets

assets/img/coop.gif

@@ -6,7 +6,7 @@ class WC_Banklink_Krediidipank_Gateway extends WC_Banklink_Ipizza {
 	function __construct() {
 		$this->id           = 'krediidipank';
 		$this->method_title = __( 'Coop pank', 'wc-gateway-estonia-banklink' );
-		$this->logo         = $this->get_option( 'logo', plugins_url( 'assets/img/coop.gif', WC_ESTONIAN_GATEWAYS_MAIN_FILE ) );
+		$this->logo         = $this->get_option( 'logo', plugins_url( 'assets/img/coop.png', WC_ESTONIAN_GATEWAYS_MAIN_FILE ) );
 
 		parent::__construct();
 	}