Fix compatibility with newer Boost.

Extracted from this upstream commit:
https://cgit.freedesktop.org/libreoffice/core/commit/?id=23a8d5ffbbe58761b89f590f0735abccd69a3681

diff --git a/sfx2/source/appl/shutdownicon.cxx b/sfx2/source/appl/shutdownicon.cxx
--- a/sfx2/source/appl/shutdownicon.cxx
+++ b/sfx2/source/appl/shutdownicon.cxx
@@ -144,7 +144,7 @@ bool LoadModule()
 #endif // ENABLE_QUICKSTART_APPLET
     }
     assert(!boost::logic::indeterminate(loaded));
-    return loaded;
+    return bool(loaded);
 }
 
 }
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<tr><td><span title='2020-01-16 23:14:05 +0100'>2020-01-16</span></td><td><a href='/guix/commit/tests/cran.scm?id=cfd1ed84013df85f0e473884ef4038b4bd7120d4'>import: cran: Avoid uses of '@@' in the tests.</a><span class='msg-avail'>...<span class='msg-tooltip'>* guix/import/cran.scm (description-&gt;alist, description-&gt;package): Export.
&lt;top level&gt;: Set! 'listify'.
* tests/cran.scm (description-alist, "description-&gt;package"): Remove use
of '@@' to access the relevant bindings.
</span></span></td><td>Ludovic Courtès</td></tr>