databases/dbtool: Unbreak with Clang 6
engine.cc:539:46: error: non-constant-expression cannot be narrowed from type
'std::__1::basic_string<char, std::__1::char_traits<char>,
std::__1::allocator<char> >::size_type' (aka 'unsigned long') to 'int' in
initializer list [-Wc++11-narrowing]
datum key = {(char *)config.key.c_str(), config.key.length()};
^~~~~~~~~~~~~~~~~~~engine.cc:539:46: note: insert an explicit cast to silence this issue
datum key = {(char *)config.key.c_str(), config.key.length()};
^~~~~~~~~~~~~~~~~~~
static_cast<int>( )http://beefy12.nyi.freebsd.org/data/head-amd64-default/p472224_s334983/logs/dbtool-1.9.1.log