版本更新下载地址增加后端返回地址，优先取接口返回地址。

KulexiuForStudent/KulexiuForStudent/AppDelegate.m

@@ -256,7 +256,7 @@
                         if ([serviceVersion isEqualToString:storeVersion] || [self isLowerVersionCompareLocalVersion:currentVersion serviceVersion:serviceVersion]) {
                             // desc
                             NSString *descMessage = [[dic ks_dictionaryValueForKey:@"data"] ks_stringValueForKey:@"description"];
-                            NSString *downloadUrl = [[dic ks_dictionaryValueForKey:@"data"] ks_stringValueForKey:@"downloadUrl"];
+                            NSString *downloadUrl = [[[dic ks_dictionaryValueForKey:@"data"] ks_stringValueForKey:@"downloadUrl"] getUrlEndcodeString];
                             // 如果没有配置
                             if ([NSString isEmptyString:downloadUrl]) {
                                 downloadUrl = openUrl;
@@ -274,7 +274,9 @@
                         
                     }
                 } faliure:^(NSError * _Nonnull error) {
-                    [self showAlertWithMemo:storeVersion descMessage:@"全新版本上线了，赶快来体验吧！" isforce:NO openUrl:openUrl];
+                    if ([self isLowerVersionCompareLocalVersion:currentVersion serviceVersion:serviceVersion]) {
+                        [self showAlertWithMemo:storeVersion descMessage:@"全新版本上线了，赶快来体验吧！" isforce:NO openUrl:openUrl];
+                    }
                 }];
             }
             else {