SpeechSynthesis.java: fix getAvailableVoices() on Android 4.3

android/src/com/reecedunn/espeak/SpeechSynthesis.java

 import java.util.List;
 import java.util.Locale;
 import java.util.Map;
+import java.util.MissingResourceException;
 
 public class SpeechSynthesis {
     private static final String TAG = SpeechSynthesis.class.getSimpleName();
                 }
             }
 
-            if (locale != null && !locale.getISO3Language().equals("")) {
-                final Voice voice = new Voice(name, identifier, gender, age, locale);
-                voices.add(voice);
+            try {
+                if (locale != null && !locale.getISO3Language().equals("")) {
+                    final Voice voice = new Voice(name, identifier, gender, age, locale);
+                    voices.add(voice);
+                }
+            } catch (MissingResourceException e) {
+                // Android 4.3 throws this exception if the 3-letter language
+                // code is missing for a locale (e.g. nci). Earlier versions
+                // of Android return an empty string.
             }
         }