Again espeak-ng upstream seems to have changed the default voice;
'Default' went away in 1.49.1 replaced by 'English', and now 'English'
went away in 1.49.2 replaced by a series of geopolitically qualified
- change the list of voices to add back an English and Spanish, since
code elsewhere in Speak relies on these names,
- assume a new default voice English (America).
Ported from https://github.com/sugarlabs/speak/commit/72d6ff14ad54b32828c971317221316dd19cef23