audio/asterisk-espeak: Update 5.0-rc1 => 5.0

Changelog:
https://github.com/zaf/Asterisk-eSpeak/blob/v5.0/ChangeLog

Improve port:

• Add flavors asterisk20 and asterisk22.
• Set default flavor to asterisk22.
• Fix warnings from portclippy.
• Refresh patch.