server returned HTTP status 404 Not Found

## Bug Report

**Describe the bug**

when we start fluent-bit , can not get prometheus metrics

root@ip-10-70-36-133:~# lsof -i:2021
COMMAND PID USER FD TYPE DEVICE SIZE/OFF NODE NAME
fluent-bi 2164251 root 74u IPv4 19834897 0t0 TCP *:2021 (LISTEN)
fluent-bi 2164251 root 108u IPv4 19834995 0t0 TCP ip-10-70-36-133.ap-northeast-1.compute.internal:2021->ip-10-70-xx-xx.ap-northeast-1.compute.internal:43444 (ESTABLISHED)

**To Reproduce**
- Rubular link if applicable:
- Example log message if applicable:
```
{"log":"YOUR LOG MESSAGE HERE","stream":"stdout","time":"2018-06-11T14:37:30.681701731Z"}
```
- Steps to reproduce the problem:

**Expected behavior**

**Screenshots**

**Your Environment**

* Version used: Fluent Bit v3.1.3
* Configuration: please see below
* Environment name and version (e.g. Kubernetes? What version?): EC2 Linux 6.8.0-1010-aws #10-Ubuntu SMP Thu Jun 13 17:36:15 UTC 2024 x86_64 x86_64 x86_64 GNU/Linux
* Server type and version:
* Operating System and version: Linux 6.8.0-1010-aws #10-Ubuntu SMP Thu Jun 13 17:36:15 UTC 2024 x86_64 x86_64 x86_64 GNU/Linux
* Filters and plugins:

**Additional context**

install service by run curl https://raw.githubusercontent.com/fluent/fluent-bit/master/install.sh | sh
root@ip-10-70-36-133:~# cat /etc/fluent-bit/fluent-bit.conf
[SERVICE]
flush 1
daemon Off
log_level info
parsers_file parsers.conf
plugins_file plugins.conf
http_server On
http_listen 0.0.0.0
http_port 2020
Health_Check On
HC_Errors_Count 5
HC_Retry_Failure_Count 5
HC_Period 5
storage.metrics on

[INPUT]
name tail
path /data/apache-shardingsphere/logs/*.log
path_key log_path
tag sharding-services
[INPUT]
name tail
path /var/log/*.log
path_key log_path
tag sharding-system

[INPUT]
Name exec
Tag prod-sharding
Interval_Sec 30
command pg_isready -h 10.70.xxx.xxx -p3307 -U sharding -d sharding_db

[INPUT]
Name proc
Proc_Name java
Interval_Sec 30
Interval_NSec 0
Fd true
Mem true
[INPUT]
name process_exporter_metrics
tag process_metrics
process_include_pattern java
scrape_interval 10

[OUTPUT]
name prometheus_exporter
match process_metrics
host 0.0.0.0
port 2021
add_label app sharding

[OUTPUT]
name loki
match *
host loki.xxx.com
port 443
tls on
labels job=fluentbit, env=prod, namespace=sharding, app=sharding-xxxx

root@ip-10-70-xxx:~# systemctl status fluent-bit
● fluent-bit.service - Fluent Bit
Loaded: loaded (/usr/lib/systemd/system/fluent-bit.service; enabled; preset: enabled)
Active: active (running) since Sat 2024-09-07 05:08:23 UTC; 10min ago
Docs: https://docs.fluentbit.io/manual/
Main PID: 2164251 (fluent-bit)
Tasks: 10 (limit: 37850)
Memory: 90.6M (peak: 132.7M)
CPU: 10min 31.477s
CGroup: /system.slice/fluent-bit.service
└─2164251 /opt/fluent-bit/bin/fluent-bit -c //etc/fluent-bit/fluent-bit.conf

Sep 07 05:12:31 ip-10-70-36-133 fluent-bit[2164251]: [2024/09/07 05:12:31] [ info] [input:tail:tail.0] inotify_fs_add(): inode=6293396 watch_fd=2 name=/data/apa>
Sep 07 05:12:31 ip-10-70-36-133 fluent-bit[2164251]: [2024/09/07 05:12:31] [ info] [input:tail:tail.1] inotify_fs_add(): inode=3584 watch_fd=1 name=/var/log/alt>
Sep 07 05:12:31 ip-10-70-36-133 fluent-bit[2164251]: [2024/09/07 05:12:31] [ info] [input:tail:tail.1] inotify_fs_add(): inode=79203 watch_fd=2 name=/var/log/ap>
Sep 07 05:12:31 ip-10-70-36-133 fluent-bit[2164251]: [2024/09/07 05:12:31] [ info] [input:tail:tail.1] inotify_fs_add(): inode=3597 watch_fd=3 name=/var/log/aut>
Sep 07 05:12:31 ip-10-70-36-133 fluent-bit[2164251]: [2024/09/07 05:12:31] [ info] [input:tail:tail.1] inotify_fs_add(): inode=79146 watch_fd=4 name=/var/log/cl>
Sep 07 05:12:31 ip-10-70-36-133 fluent-bit[2164251]: [2024/09/07 05:12:31] [ info] [input:tail:tail.1] inotify_fs_add(): inode=78496 watch_fd=5 name=/var/log/cl>
Sep 07 05:12:31 ip-10-70-36-133 fluent-bit[2164251]: [2024/09/07 05:12:31] [ info] [input:tail:tail.1] inotify_fs_add(): inode=21 watch_fd=6 name=/var/log/dpkg.>
Sep 07 05:12:31 ip-10-70-36-133 fluent-bit[2164251]: [2024/09/07 05:12:31] [ info] [input:tail:tail.1] inotify_fs_add(): inode=79335 watch_fd=7 name=/var/log/fo>
Sep 07 05:12:31 ip-10-70-36-133 fluent-bit[2164251]: [2024/09/07 05:12:31] [ info] [input:tail:tail.1] inotify_fs_add(): inode=3083 watch_fd=8 name=/var/log/ker>
Sep 07 05:12:31 ip-10-70-36-133 fluent-bit[2164251]: [2024/09/07 05:12:31] [ info] [input:tail:tail.1] inotify_fs_add(): inode=3599 watch_fd=9 name=/var/log/ubu>
lines 1-21/21 (END)

root@ip-10-70-36-133:~# curl http://10.70.36.133:2021/metrics
root@ip-10-70-36-133:~# curl http://10.70.36.133:2021/metrics -I
HTTP/1.1 404 Not Found
Server: Monkey/1.7.2
Date: Sat, 07 Sep 2024 05:20:34 GMT
Transfer-Encoding: chunked

root@ip-10-70-36-133:~# curl http://localhost:2021/metrics
root@ip-10-70-36-133:~# curl http://localhost:2021/metrics -I
HTTP/1.1 404 Not Found
Server: Monkey/1.7.2
Date: Sat, 07 Sep 2024 05:20:59 GMT
Transfer-Encoding: chunked

root@ip-10-70-36-133:~#