fix leaking of open faces destroyed from different thread

6 jobs for thread_local_open_faces_cache in 3 minutes and 46 seconds (queued for 2 seconds)
latest
Status Job ID Name Coverage
  Build
passed #1536604
build

00:03:46

passed #1536609
build_android

00:01:42

passed #1536605
build_clang_libcpp

00:03:41

passed #1536608
build_clazy

00:02:22

passed #1536607
build_mingw64_fedora

00:03:20

passed #1536606
build_ubuntu_16_04

00:01:44