Set defaults for anti-aliasing using the krdb

We used to write a configuration for the anti-aliasing using the
startkde script, startkde script would write to kdeglobals and then read
this configuration in the krdb.

This had un-intended side-effect of $XDG_CONFIG_DIRS/kdeglobals settings
or settings set by ~/.config/fontconfig/fonts.conf not being used.

D21335 fixes this by not writing to kdeglobals anymore, this transfers
the defaults used by startkde here.

CCBUG: 389598
CCBUG: 407754