Silence EPIPE warning when closing reconfigs
Silence EPIPE warning when closing reconfigs

ShareableFileReader should be pruning the "watcher" pipe write ends from
ShareableFile so that we don't end up trying to write into a closed pipe,
but doing this is hard and not necessary.  As a workaround, just ignore
EPIPE errors to avoid a harmless warning when exiting sandboxfs.

bazelbuild/sandboxfs,bazelbuild/sandboxfs,bazelbuild/sandboxfs