Fix enforcing of nametag hiding

Commit

d2ca6625 "Enforce hiding nametag"

didn't fix the issue for "client" instances, where the nametag update
was received before the object was added to the scene. This resulted
in the grey shadow on the nametag that commit tried to fix.

Thanks to @neoascetic for pointing out that there still is a shadow.

src/content_cao.cpp

@@ -975,6 +975,11 @@ void GenericCAO::addToScene(scene::ISceneManager *smgr, ITextureSource *tsrc,
 				wname.c_str(), m_nametag_color, node);
 		m_textnode->grab();
 		m_textnode->setPosition(v3f(0, BS*1.1, 0));
+
+		// Enforce hiding nametag,
+		// because if freetype is enabled, a grey
+		// shadow can remain.
+		m_textnode->setVisible(m_nametag_color.getAlpha() > 0);
 	}
 
 	updateNodePos();