Fix ESpeak to use Stdin instead of a shell argument

tts/espeak/index.js

@@ -6,6 +6,7 @@ module.exports=class extends BaseEngine {
 		super('ESpeak','wav')
 	}
 	async getSpeechFile(text, filepath, voice='en', params={}) {
-		await spawn('espeak', ['-v', voice, '-w',filepath, text]);
+		let proc=await spawn('espeak', ['-v', voice, '-w',filepath, '--stdin']);
+		proc.stdin.end(text);
 	}
 }