The Struve-Sahade effect in the optical spectra of O-type binaries - I. Main-sequence systems (Corrigendum)N. Linder, G. Rauw, H. Sana, M. De Becker and E. GossetA&A, 541 (2012) C2DOI: https://doi.org/10.1051/0004-6361/20077902e