[PR] fix(remoting): match every address for a /0 CIDR in ipInCIDR [rocketmq]

["zjncs (via GitHub)" <gi...@apache.org>]

zjncs opened a new pull request, #11068:
URL: https://github.com/apache/rocketmq/pull/11068

   ### Motivation
   
   `RemotingHelper.ipInCIDR` computes the netmask as:
   
   ```java
   int mask = 0xFFFFFFFF << (32 - netId);
   ```
   
   For `netId == 0` the shift distance is 32, which Java takes mod 32 — the shift is a no-op and `mask` stays `0xFFFFFFFF` instead of `0`. So a `/0` CIDR matches nothing except its own address:
   
   ```java
   ipInCIDR("1.2.3.4", "0.0.0.0/0")  // returns false, should be true
   ```
   
   Reachability: `NettyRemotingClient.getProxy` guards only the exact string `"0.0.0.0/0"` (`DEFAULT_CIDR_ALL.equals(cidr)`) before calling `ipInCIDR`, so a socks proxy configured with any other `/0` CIDR (e.g. `10.0.0.0/0`) silently never matches and the traffic bypasses the configured proxy. `/1`–`/32` are unaffected.
   
   ### Modifications
   
   Use a zero mask when the prefix length is 0.
   
   ### Verification
   
   Fail-before (new test class `RemotingHelperTest`, run against the unpatched code):
   
   ```
   Tests run: 2, Failures: 1 -- RemotingHelperTest#testIpInCidrMatchesEverythingForZeroPrefixLength
   ```
   
   Pass-after:
   
   ```
   Tests run: 2, Failures: 0, Errors: 0, Skipped: 0 -- RemotingHelperTest
   ```
   


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