gnu: Remove python-nltk-3.4.

* gnu/packages/python-xyz.scm (python-nltk-3.4): Remove variable.

Change-Id: I865380c0428d459147c0980065719c32bf67075a

gnu/packages/python-xyz.scm

@@ -21721,20 +21721,6 @@ JSON) codec.")
      reasoning, wrappers for natural language processing libraries.")
     (license license:asl2.0)))
 
-;; Versions >=3.5 breaks backward-compatibility,
-;; so we keep version 3.4.x around for a while.
-(define-public python-nltk-3.4
-  (package
-    (inherit python-nltk)
-    (version "3.4.5")
-    (source
-     (origin
-       (method url-fetch)
-       (uri (pypi-uri "nltk" version ".zip"))
-       (sha256
-        (base32 "153x2clrnigs74jdgnn3qmljdjj4gprmvpdvh49i18ls4m8mbm5y"))))
-    (propagated-inputs (list python-six))))
-
 (define-public python-pymongo
   (package
     (name "python-pymongo")