multiplexing: ignore exceptions when reading from hooks.
multiplexing: ignore exceptions when reading from hooks.

Some multiplexing hooks such as storage endpoints throw when
attempting to read from them. Such thing happened when the
multiplexing engine was shutting down. Such exceptions are now
ignored.

git-svn-id: a49aa41e49c69a6ab6ef43f172843a2fef6cb475@1308 7c7d615a-03b3-410d-a316-1135b1bd9499

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