Kvod Harav, is one allowed to repair during the three weeks wall paper that fell of a wall, by just gluing it back to the wall

Kovetz Halochos (5: 19) quotes Igros Moshe (O.H. 3: 82) regarding placing new wall paper during the Nine Days. However, just gluing back existing paper that fell, Poskim permit.(See Nitei Gavriel 29: 3)