fix warning in windows debug build

> o3tl/typed_flags_set.hxx(82) : warning C4309: ´static_cast´ :
>                                truncation of constant value



Change-Id: I396b68e47d682ffe90ba3afb2ebf846cf100e20c
Reviewed-on: https://gerrit.libreoffice.org/28977Reviewed-by: Jochen Nitschke <j.nitschke+logerrit@ok.de>
Tested-by: Jochen Nitschke <j.nitschke+logerrit@ok.de>

include/o3tl/typed_flags_set.hxx

@@ -80,7 +80,7 @@ struct is_typed_flags {
 #if !HAVE_CXX11_CONSTEXPR || HAVE_CXX14_CONSTEXPR
             assert(detail::isNonNegative(value));
             assert(
-                static_cast<typename std::underlying_type<E>::type>(~M) == 0
+                static_cast<typename std::underlying_type<E>::type>(~0) == M
                     // avoid "operands don't affect result" warnings when M
                     // covers all bits of the underlying type
                 || (value & ~M) == 0);