Fix "no matching sound" error spam

Previously, the error message was only silenced for openclonk-server,
but appeared for openclonk if compiled without sounds.

Possible side effect: no local sounds will play if the global Sound.ocg
cannot be loaded. I don't think this is something we should support.

src/platform/C4SoundSystem.cpp

@@ -50,11 +50,13 @@ bool C4SoundSystem::Init()
 #if AUDIO_TK == AUDIO_TK_SDL_MIXER
 	Mix_AllocateChannels(C4MaxSoundInstances);
 #endif
+	initialized = true;
 	return true;
 }
 
 void C4SoundSystem::Clear()
 {
+	initialized = false;
 	ClearEffects();
 	Modifiers.Clear();
 	// Close sound file
@@ -122,15 +124,13 @@ C4SoundEffect* C4SoundSystem::GetEffect(const char *szSndName)
 C4SoundInstance *C4SoundSystem::NewEffect(const char *szSndName, bool fLoop, int32_t iVolume, C4Object *pObj, int32_t iCustomFalloffDistance, int32_t iPitch, C4SoundModifier *modifier)
 {
 	// Sound not active
-	if (!Config.Sound.RXSound) return nullptr;
+	if (!initialized || !Config.Sound.RXSound) return nullptr;
 	// Get sound
 	C4SoundEffect *csfx;
 	if (!(csfx = GetEffect(szSndName)))
 	{
 		// Warn about missing or incorrectly spelled sound to allow finding mistakes earlier.
-#if !defined(USE_CONSOLE)
 		DebugLogF("Warning: could not find sound matching '%s'", szSndName);
-#endif
 		return nullptr;
 	}
 	// Play

src/platform/C4SoundSystem.h

@@ -55,6 +55,7 @@ public:
 protected:
 	C4Group SoundFile;
 	C4SoundEffect *FirstSound{nullptr}; // TODO: Add a hash map for sound lookup. Also add a global list for all running sound instances.
+	bool initialized{false};
 	void ClearEffects();
 	C4SoundEffect* GetEffect(const char *szSound);
 	int32_t RemoveEffect(const char *szFilename);