util: Include fmt/ranges.h in config_file.hh

The operator() of named_value() prints the allowed values on error which
can be a vector, so the ranges formatting should be there.

Signed-off-by: Pavel Emelyanov <xemul@scylladb.com>

utils/config_file.hh

@@ -11,6 +11,8 @@
 
 #include <fmt/format.h>
 #include <fmt/ostream.h>
+#include <fmt/ranges.h>
+
 #include <unordered_map>
 #include <iosfwd>
 #include <string_view>