[kea-dev] Missing boost header file in 3.0.2

[Philip Prindeville]

I'm trying to build kea-3.0.2 on OpenWRT HEAD and it's regressed, probably because of toolchain updates.

Apparently src/lib/log/logger_level_impl.cc <http://logger_level_impl.cc/> needs <boost/static_assert.hpp> to be included.