Comment # 1 on bug 1191030 from Gabriele Sonnu

Affected Packages:

 - openSUSE:Backports:SLE-15-SP2/python-nltk  3.4.5
 - openSUSE:Backports:SLE-15-SP3/python-nltk  3.4.5
 - openSUSE:Backports:SLE-15-SP4/python-nltk  3.4.5
 - openSUSE:Factory/python-nltk               3.5

Upstream patch:
https://github.com/nltk/nltk/commit/277711ab1dec729e626b27aab6fa35ea5efbd7e6