remove bad backslashes in doc/sphinx/api.rst
remove bad backslashes in doc/sphinx/api.rst

Thanks Pierre
<20190416132442.GI5269@di.ens.fr>

wetneb/dissemin,wetneb/dissemin,dissemin/dissemin,dissemin/dissemin,wetneb/dissemin,dissemin/dissemin,dissemin/dissemin,wetneb/dissemin,dissemin/dissemin