- [x] I have searched the [issues](https://github.com/apache/dubbo/issues) of this repository and believe that this is not a duplicate.
- [x] I have checked the [FAQ](https://github.com/apache/dubbo/blob/master/FAQ.md) of this repository and believe that this is not a duplicate.

### Environment

* Dubbo version: 2.7.6
* Operating System version: CentOS-7
* Java version: 1.8.0_275

### Steps to reproduce this issue

dobbo use netty to listen as a server .  and use this class SslConfig.java  and netty4/SslContexts.java to use ssl cert file .
this class always open file .
by netty's source :  PemReader and SslContextBuilder they not close this InputStream yet .and netty expect user close the InputStream if the InputStream is open by user.

https://github.com/netty/netty/issues/10974
https://github.com/netty/netty/pull/10976

but it seems dobbo not close it ?

![image](https://user-images.githubusercontent.com/5086059/106403950-e61ef980-646b-11eb-9d8d-2c21550e4954.png)

![image](https://user-images.githubusercontent.com/5086059/106403961-ecad7100-646b-11eb-929e-5ec79837886d.png)

Pls. provide [GitHub address] to reproduce this issue.

### Expected Result

InputStream maybe need close immediately?

### Actual Result

InputStream seems leak.


} catch (Exception e) {
            throw new IllegalArgumentException("Could not find certificate file or find invalid certificate.", e);
        }
        try {
            return builder.sslProvider(findSslProvider()).build();
        } catch (SSLException e) {
            throw new IllegalStateException("Build SslSession failed.", e);
        }
    }
    /**
     * Returns OpenSSL if available, otherwise returns the JDK provider.
     */
    private static SslProvider findSslProvider() {
        if (OpenSsl.isAvailable()) {
            logger.info("Using OPENSSL provider.");
            return SslProvider.OPENSSL;
        } else if (checkJdkProvider()) {
            logger.info("Using JDK provider.");
            return SslProvider.JDK;
        }
        throw new IllegalStateException(
                "Could not find any valid TLS provider, please check your dependency or deployment environment, " +
                        "usually netty-tcnative, Conscrypt, or Jetty NPN/ALPN is needed.");
    }
    private static boolean checkJdkProvider() {
        Provider[] jdkProviders = Security.getProviders("SSLContext.TLS");
        return (jdkProviders != null && jdkProviders.length > 0);
    }
}