CAudioManager: Make constructor explicit

Prevents potentially error-prone constructions from occurring

src/Core/CAudioManager.h

@@ -26,7 +26,7 @@ class CAudioManager
     std::unordered_map<uint16, CAudioGroup*> mSfxIdMap;
 
 public:
-    CAudioManager(CGameProject *pProj);
+    explicit CAudioManager(CGameProject *pProj);
     void LoadAssets();
     void ClearAssets();
     SSoundInfo GetSoundInfo(uint32 SoundID);