gnu: libreoffice: Fix FTBFS with Boost 1.69.0.

* gnu/packages/patches/libreoffice-boost.patch: New file.
* gnu/local.mk (dist_patch_DATA): Adjust accordingly.
* gnu/packages/libreoffice.scm (libreoffice)[source](patches): Add it.

gnu/local.mk

@@ -977,6 +977,7 @@ dist_patch_DATA =						\
   %D%/packages/patches/libmad-mips-newgcc.patch			\
   %D%/packages/patches/libmygpo-qt-fix-qt-5.11.patch		\
   %D%/packages/patches/libmygpo-qt-missing-qt5-modules.patch	\
+  %D%/packages/patches/libreoffice-boost.patch			\
   %D%/packages/patches/libreoffice-icu.patch			\
   %D%/packages/patches/libreoffice-glm.patch			\
   %D%/packages/patches/libsndfile-armhf-type-checks.patch	\

gnu/packages/libreoffice.scm

@@ -997,7 +997,8 @@ converting QuarkXPress file format.  It supports versions 3.1 to 4.1.")
                         (sha256
                          (base32
                           "1dsd0gynjf7d6412dd2sx70xa2s8kld7ibyjdkwg5w9hhi2zxw2f"))))
-                (search-patches "libreoffice-icu.patch"
+                (search-patches "libreoffice-boost.patch"
+                                "libreoffice-icu.patch"
                                 "libreoffice-glm.patch")))
        (modules '((guix build utils)))
        (snippet

gnu/packages/patches/libreoffice-boost.patch

@@ -0,0 +1,17 @@
+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);
+ }
+ 
+ }