为什么我的tomcat在端口80上无法访问?

我改变了我的服务器.xml这样地:

    <Connector port="8080" protocol="HTTP/1.1"
               connectionTimeout="20000"
               redirectPort="8443" />

<Connector port="80"
           protocol="HTTP/1.1"
           connectionTimeout="20000"
           redirectPort="8443"
           URIEncoding="UTF-8" />

重启了tomcat。

sudo yum remove httpd

但tomcat仍然只能在8080上工作:

curl localhost:80
curl: (7) Failed connect to localhost:80; Verbindungsaufbau abgelehnt