patch 9.0.1905: FEAT_FLOAT no longer defined

patch 9.0.1905: FEAT_FLOAT no longer defined

Problem:  FEAT_FLOAT no longer defined
Solution: Remove last existing FEAT_FLOAT ifdefs in
          message_test

Remove FEAT_FLOAT as that should always be true

FEAT_FLOAT has been removed in v9.0.0491 (73e28dcc6125f616cf1f2) but
unfortunately, it was forgotten to remove it from message_test.c. So
let's remove the last mentioned ifdefs which are now unused.

closes: #13106

Signed-off-by: Christian Brabandt <cb@256bit.org>
Co-authored-by: dundargoc <gocdundar@gmail.com>