奇怪的HTTP 415问题

1、我用curl工具发post请求，是完全可以的：

#!/bin/sh -ex

url="https://olvmm/ovirt-engine/api"
user="admin@internal"
password="1234"
curl \
--verbose \
--cacert /etc/ca.cer \
--user "${user}:${password}" \
--request POST \
--header "Version: 4" \
--header "Content-Type: application/xml" \
--header "Accept: application/xml" \
--data '
<vm>
  <name>myvm</name>
  <template>
    <name>cloud-init-new</name>
  </template>
  <cluster>
    <name>Cluster1</name>
  </cluster>
</vm>
' \
"${url}/vms"

中间结果省略

    </sso>
    <start_paused>false</start_paused>
    <stateless>false</stateless>
    <storage_error_resume_behaviour>auto_resume</storage_error_resume_behaviour>
    <time_zone>
        <name>Etc/GMT</name>
    </time_zone>
    <type>server</type>
    <usb>
        <enabled>false</enabled>
    </usb>
    <virtio_scsi>
        <enabled>true</enabled>
    </virtio_scsi>
    <cluster href="/ovirt-engine/api/clusters/47e60102-cb8e-11eb-82fd-5254007ff509" id="47e60102-cb8e-11eb-82fd-5254007ff509"/>
    <cpu_profile href="/ovirt-engine/api/cpuprofiles/58ca604e-01a7-003f-01de-000000000250" id="58ca604e-01a7-003f-01de-000000000250"/>
    <quota id="4e1728e4-cb8e-11eb-b8a1-5254007ff509"/>
    <next_run_configuration_exists>false</next_run_configuration_exists>
    <numa_tune_mode>interleave</numa_tune_mode>
    <status>image_locked</status>
    <stop_time>2021-08-13T19:01:41.093+08:00</stop_time>
    <original_template href="/ovirt-engine/api/templates/fc480cbb-1a05-48a8-9c34-0bc4cc69a154" id="fc480cbb-1a05-48a8-9c34-0bc4cc69a154"/>
    <template href="/ovirt-engine/api/templates/fc480cbb-1a05-48a8-9c34-0bc4cc69a154" id="fc480cbb-1a05-48a8-9c34-0bc4cc69a154"/>
</vm>
* Connection #0 to host olvmm left intact
 

2、但是一样的命令在RESTClient里面就报错：

请问这是什么原因？
 

Content-Type设置值可能有误