gnu: r-plotrix: Update to 3.7-4.

* gnu/packages/statistics.scm (r-plotrix): Update to 3.7-4.

gnu/packages/statistics.scm

@@ -2459,13 +2459,13 @@ disk (or a connection).")
 (define-public r-plotrix
   (package
     (name "r-plotrix")
-    (version "3.7-3")
+    (version "3.7-4")
     (source (origin
               (method url-fetch)
               (uri (cran-uri "plotrix" version))
               (sha256
                (base32
-                "18702y1gbyis56mh219z5ww0nrkh6qx7bgqv3khyn80g2giwk7cf"))))
+                "1hs0zwaqs34559girinvysjfbvznyn8znp9cwvkqx6k2cqvcjinj"))))
     (build-system r-build-system)
     (home-page "https://cran.r-project.org/web/packages/plotrix")
     (synopsis "Various plotting functions")