HPCC-16090 - Build error on Clang in new logging code

Signed-off-by: Richard Chapman <rchapman@hpccsystems.com>

esp/logging/loggingagent/espserverloggingagent/loggingagent.cpp

@@ -165,7 +165,7 @@ void CESPServerLoggingAgent::createLocalTransactionSeed(StringBuffer& transactio
     unsigned ip = queryHostIP().iphash();
     unsigned mstick6char = ((unsigned)usTick() & 0xFFFFFF);
     unsigned processId2char = ((unsigned)GetCurrentProcessId()) & 0xF;
-    unsigned threadId1char = ((unsigned)GetCurrentThreadId()) & 0xF;
+    unsigned threadId1char = ((unsigned) (memsize_t) GetCurrentThreadId()) & 0xF;
     transactionSeed.setf("%02X%06X%X%X", ip, mstick6char, processId2char, threadId1char);
 }