This is safe because MilliSleep is never executed in a boost::thread,
the only type of thread that is interruptible.
* The RPC server uses std::thread
* The wallet is either executed in an RPC thread or the main thread
* bitcoin-cli, benchmarks and tests are only one thread (the main thread)
-BEGIN VERIFY SCRIPT-
sed -i --regexp-extended -e 's/MilliSleep\((\S+)\);/UninterruptibleSleep(std::chrono::milliseconds{\1});/g' $(git grep -l MilliSleep)
-END VERIFY SCRIPT-