Merge pull request #607 from DonLakeFlyer/ESpeakWarnings

Fix GCC compiler warning

src/GAudioOutput.cc

@@ -97,10 +97,12 @@ GAudioOutput::GAudioOutput(QObject *parent) : QObject(parent),
 
 #if defined Q_OS_LINUX && defined QGC_SPEECH_ENABLED
     espeak_Initialize(AUDIO_OUTPUT_PLAYBACK, 500, NULL, 0); // initialize for playback with 500ms buffer and no options (see speak_lib.h)
-    espeak_VOICE espeak_voice = {};
+    espeak_VOICE espeak_voice;
     espeak_voice.languages = "en-uk"; // Default to British English
+    espeak_voice.identifier = NULL; // no specific voice file specified
     espeak_voice.name = "klatt"; // espeak voice name
     espeak_voice.gender = 2; // Female
+    espeak_voice.age = 0; // age not specified
     espeak_SetVoiceByProperties(&espeak_voice);
 #endif