Use a dummy enum declaration to avoid duplicate Lua global constants.

Source/Urho3D/LuaScript/pkgs/Audio/SoundSource.pkg

@@ -1,11 +1,7 @@
 $#include "Audio/SoundSource.h"
 
-enum AutoRemoveMode
-{
-    REMOVE_DISABLED = 0,
-    REMOVE_COMPONENT,
-    REMOVE_NODE
-};
+// The actual enum is defined in Scene/Component.pkg
+enum AutoRemoveMode {};
 
 class SoundSource : public Component
 {

Source/Urho3D/LuaScript/pkgs/Graphics/ParticleEmitter.pkg

@@ -1,11 +1,7 @@
 $#include "Graphics/ParticleEmitter.h"
 
-enum AutoRemoveMode
-{
-    REMOVE_DISABLED = 0,
-    REMOVE_COMPONENT,
-    REMOVE_NODE
-};
+// The actual enum is defined in Scene/Component.pkg
+enum AutoRemoveMode {};
 
 class ParticleEmitter : public BillboardSet
 {
@@ -38,4 +34,4 @@ ${
 
 #define TOLUA_DISABLE_tolua_set_ParticleEffect_numTextureFrames
 #define tolua_set_ParticleEffect_numTextureFrames NULL
-$}
+$}