Workaround a doxygen crash.

Macports Doxygen 1.5.8 is crashing for me without this change, Ubuntu doxygen
1.5.6 is fine so I assume this is a bug in recent versions.


[SVN r52006]

libs/interprocess

@@ -1 +1 @@
-Subproject commit eceee3234ee0f574706ad0b60df0309606a8ef83
+Subproject commit 12ace1eb5412d3e68d801f618d0ee4fbd7277ab9