[fix](meta) add sync new image timeout

fe/fe-common/src/main/java/org/apache/doris/common/Config.java

@@ -2259,4 +2259,13 @@ public class Config extends ConfigBase {
     })
     public static boolean ignore_unknown_metadata_module = false;
 
+    @ConfField(mutable = true, masterOnly = true, description = {
+        "FE扩容时，从主节点同步元数据的timeout时间，根据${meta_dir}/image文件夹下面的image文件大小和节点间的网络环境调整，"
+            + "单位为秒，默认值300",
+        "The timeout for new FE Follower/Observer synchronizing metadata from the FE Master, "
+            + "adjust by the size of image file in the ${meta_dir}/image and the network environment between nodes. "
+            + "The default values is 300s."
+    })
+    public static int sync_image_timeout_second = 300;
+
 }

fe/fe-core/src/main/java/org/apache/doris/catalog/Env.java

@@ -1726,7 +1726,8 @@ private void getNewImage(HostInfo helperNode) throws IOException {
                 String url = "http://" + hostPort + "/image?version=" + version;
                 String filename = Storage.IMAGE + "." + version;
                 File dir = new File(this.imageDir);
-                MetaHelper.getRemoteFile(url, HTTP_TIMEOUT_SECOND * 1000, MetaHelper.getFile(filename, dir));
+                MetaHelper.getRemoteFile(url, Config.sync_image_timeout_second * 1000,
+                        MetaHelper.getFile(filename, dir));
                 MetaHelper.complete(filename, dir);
             } else {
                 LOG.warn("get an image with a lower version, localImageVersion: {}, got version: {}",