Prevent client crashing if an NDT_AIRLIKE node is dropped

The player dropping the node can either be themselves or another player (i.e. without this fix you can crash other people's clients)
Thanks CWz for reporting the issue

src/wieldmesh.cpp

@@ -411,20 +411,20 @@ void WieldMeshSceneNode::changeToMesh(scene::IMesh *mesh)
 		m_meshnode->setVisible(false);
 		m_meshnode->setMesh(dummymesh);
 		dummymesh->drop();  // m_meshnode grabbed it
-	}
-
-	if (m_lighting) {
-		m_meshnode->setMesh(mesh);
 	} else {
-		/*
-			Lighting is disabled, this means the caller can (and probably will)
-			call setColor later. We therefore need to clone the mesh so that
-			setColor will only modify this scene node's mesh, not others'.
-		*/
-		scene::IMeshManipulator *meshmanip = SceneManager->getMeshManipulator();
-		scene::IMesh *new_mesh = meshmanip->createMeshCopy(mesh);
-		m_meshnode->setMesh(new_mesh);
-		new_mesh->drop();  // m_meshnode grabbed it
+		if (m_lighting) {
+			m_meshnode->setMesh(mesh);
+		} else {
+			/*
+				Lighting is disabled, this means the caller can (and probably will)
+				call setColor later. We therefore need to clone the mesh so that
+				setColor will only modify this scene node's mesh, not others'.
+			*/
+			scene::IMeshManipulator *meshmanip = SceneManager->getMeshManipulator();
+			scene::IMesh *new_mesh = meshmanip->createMeshCopy(mesh);
+			m_meshnode->setMesh(new_mesh);
+			new_mesh->drop();  // m_meshnode grabbed it
+		}
 	}
 
 	m_meshnode->setMaterialFlag(video::EMF_LIGHTING, m_lighting);