Fix pull_task to enforce server-required minimum timeout#4198

YuanTingHsieh wants to merge 4 commits intoNVIDIA:mainNVIDIA/NVFlare:mainfrom

YuanTingHsieh:enforce-min-get-task-timeoutYuanTingHsieh/NVFlare:enforce-min-get-task-timeoutCopy head branch name to clipboard