Fix double-free error that occurs when an exception is thrown from a

handler that has been dispatched (i.e. not posted) through a strand.


[SVN r43879]

libs/asio

@@ -1 +1 @@
-Subproject commit 601a882f6e2397225873ec2bd3fe83f92e480650
+Subproject commit 5ba249c3d1a7ef4327d1435b6516ffe57645a36e