sonnet compile failure with huspell

[Jonathan Riddell]

xenial has huspell 1.3.3 which sonnet now failes to compile with

https://build.neon.kde.org/job/xenial_unstable_kde_sonnet_bin_amd64/171/console

this seems like a deliberate decision of frameworks devs so this is
just to note the issue here, we can safely ignore it I think and just
live with xenial sonnet not compiling

frameworks patch:
https://phabricator.kde.org/D11193

bionic has huspell 1.6.2 which compiles good

Jonathan