app-text/enchant: explicitly disable applespell

app-text/enchant: explicitly disable applespell

Apparently if gnustep is installed, there's a Cocoa.h header, and the
autodetection in enchant decides that applespell should be built (and
fail at doing so).
Just explicitly disable it to fix build issues in such situations.

Also explicitly disable zemberek while at it, but the default for that
already is "no", not "check", so not a real change.

Closes: https://bugs.gentoo.org/718634
Package-Manager: Portage-2.3.84, Repoman-2.3.20
Signed-off-by: Mart Raudsepp <leio@gentoo.org>