Erratum: Spectropolarimetric observations of the CIZA J2242.8+5301 northern radio relic: no evidence of high-frequency steepening. Issue 3 (9th January 2021) - Loi, F; Murgia, M; Vacca, V; Govoni, F; Melis, A; Wittor, D; Beck, R; Kierdorf, M; Bonafede, A; Boschin, W; Brienza, M; Carretti, E; et al.