boost: Rebuild with icu-56.1

mingw-w64-boost/PKGBUILD

@@ -5,7 +5,7 @@ pkgbase=mingw-w64-${_realname}
 pkgname="${MINGW_PACKAGE_PREFIX}-${_realname}"
 pkgver=1.59.0
 _boostver=${pkgver//./_}
-pkgrel=2
+pkgrel=3
 pkgdesc="Free peer-reviewed portable C++ source libraries (mingw-w64)"
 arch=('any')
 url="http://www.boost.org/"