Fix possible crash when loading applying a skeletal twice in one frame.

Possibly a regression from 300f326777.

BBGE/RenderObject.cpp

@@ -967,6 +967,10 @@ void RenderObject::enqueueChildDeletion(RenderObject *r)
 {
 	if (r->parent == this)
 	{
+		// Don't garbage a child more than once
+		for (size_t i = 0; i < childGarbage.size(); ++i)
+			if(childGarbage[i] == r)
+				return;
 		childGarbage.push_back(r);
 	}
 }

BBGE/SkeletalSprite.cpp

@@ -1105,7 +1105,6 @@ void SkeletalSprite::deleteBones()
 	{
 		(*it)->safeKill();
 	}
-	bones.clear();
 }
 
 Animation *SkeletalSprite::getAnimation(const std::string& anim)