[Bug] SOCKS proxy CIDR matching throws NumberFormatException for hostname or IPv6 addresses, so the client cannot connect #11483

Before Creating the Bug Report

• I found a bug, not just asking a question, which should be created in GitHub Discussions.
• I have searched the GitHub Issues and GitHub Discussions of this repository and believe that this is not a duplicate.
• I have confirmed that this bug belongs to the current repository, not other repositories of RocketMQ.

Runtime platform environment

Any (reproduced on macOS)

RocketMQ version

develop, git commit id: 57c2dc0

JDK Version

JDK 17

Describe the Bug

NettyRemotingClient#getProxy picks a SOCKS proxy by matching the target host against each CIDR key of socksProxyConfig. For every key other than the literal 0.0.0.0/0 it calls RemotingHelper#ipInCIDR(host, cidr), which parses the host with ipToInt and only accepts dotted IPv4 literals.

When the target address uses a hostname (e.g. namesrv.example.com:9876, common with Kubernetes service names) or an IPv6 literal, ipToInt throws NumberFormatException. The exception escapes getProxy → fetchBootstrap → doConnect, so the client cannot connect to that address at all, even though it should just not match that CIDR.

Steps to Reproduce

NettyClientConfig config = new NettyClientConfig();
config.setSocksProxyConfig("{\"10.0.0.0/8\":{\"addr\":\"127.0.0.1:1080\"}}");
NettyRemotingClient client = new NettyRemotingClient(config);
// any invoke against "namesrv.example.com:9876" reaches getProxy(...)

Calling getProxy("namesrv.example.com:9876") (e.g. via reflection) throws:

java.lang.NumberFormatException: For input string: "namesrv"
	at org.apache.rocketmq.remoting.common.RemotingHelper.ipToInt(RemotingHelper.java)
	at org.apache.rocketmq.remoting.common.RemotingHelper.ipInCIDR(RemotingHelper.java)
	at org.apache.rocketmq.remoting.netty.NettyRemotingClient.getProxy(NettyRemotingClient.java)

What Did You Expect to See?

A hostname or IPv6 host that cannot be compared against an IPv4 CIDR does not match that entry (no proxy, direct connection), and can still match the 0.0.0.0/0 catch-all entry.

What Did You See Instead?

NumberFormatException is thrown and the connection attempt fails.

Additional Context

This is separate from #11068, which fixes the /0 mask computation inside ipInCIDR. The fix proposed here only touches NettyRemotingClient#getProxy, so the two changes do not overlap.