curl: heap-use-after-free in curl_easy_cleanup() called from callback

Summary: Curlclose lib/url.c:214 calls curlmultiremovehandledata-multi, data and ignores the return value. When curleasycleanup is invoked from within a write/read/progress/header callback, multi-incallback is TRUE, so curlmultiremovehandle lib/multi.c:818-819 returns CURLMRECURSIVEAPICALL withou...