Remove duplicate names.

The removed names also appear as:
Andrés García, François Charlier, Gökhan Şengün, Michał Górny, Sébastien
Willemijns, Christopher Conroy, John E. Malmberg, Luca Altea, Peter Su,
S. Moonesamy, Samuel Listopad, Yasuharu Yamada, Karl Moerder