[bugfix]image change

pages/course/index.vue

@@ -53,7 +53,7 @@ export default {
 			return this.useful === '1';
 		},
 		tipTextCpd() {
-			if (this.isUsefulCpd) {
+			if (!this.isUsefulCpd) {
 				return 'How to install Denet Chrome Extension';
 			} else if (this.isCommonCpd) {
 				return 'Install DeNet chrome extension to claim your prize';