[declarative] Slightly more informative warning message when sending emtpy message
[declarative] Slightly more informative warning message when sending emtpy message

Reviewed-by: Alexandr Akulich <ad71d6ef874ccc09e1a69fe0dd6443b72073e71a@gmail.com>

KDE/ktp-common-internals,KDE/ktp-common-internals,KDE/ktp-common-internals