gnu: tzdata: Update to 2018d.

* gnu/packages/base.scm (tzdata): Update to 2018d.

gnu/packages/base.scm

@@ -1105,7 +1105,7 @@ command.")
 (define-public tzdata
   (package
     (name "tzdata")
-    (version "2018c")
+    (version "2018d")
     (source (origin
              (method url-fetch)
              (uri (string-append
@@ -1113,7 +1113,7 @@ command.")
                    version ".tar.gz"))
              (sha256
               (base32
-               "1xik57rdi7kqa0wb5jbz7vyjyxpr88lw1g4kscj0ylpgnzjc6998"))))
+               "0m6020dnk9r40z7k36jp13fa06xip3hn0fdx3nly66jzxgffs1ji"))))
     (build-system gnu-build-system)
     (arguments
      '(#:tests? #f
@@ -1163,7 +1163,7 @@ command.")
                                 version ".tar.gz"))
                           (sha256
                            (base32
-                            "0rg6s1vlgwd8sjhla55hx2h5m2xbx0shm347pkbg4vsaz707zyii"))))))
+                            "1nd882yhsazmcfqmcqyfig3axycryl30gmizgqhqsx5dpa2lxr3x"))))))
     (home-page "https://www.iana.org/time-zones")
     (synopsis "Database of current and historical time zones")
     (description "The Time Zone Database (often called tz or zoneinfo)