gnu: arb: Fetch sources from git.

* gnu/packages/algebra.scm (arb)[source]: Fetch from git.

gnu/packages/algebra.scm

@@ -379,14 +379,14 @@ fast arithmetic.")
     (name "arb")
     (version "2.14.0")
     (source (origin
-            (method url-fetch)
-            (uri (string-append
-                  "https://github.com/fredrik-johansson/arb/archive/"
-                  version ".tar.gz"))
-            (file-name (string-append name "-" version ".tar.gz"))
+              (method git-fetch)
+              (uri (git-reference
+                    (url "https://github.com/fredrik-johansson/arb.git")
+                    (commit version)))
+              (file-name (git-file-name name version))
               (sha256
                (base32
-                "0ncr27nd20xxi18nj30cvpa6r52v59nq7gbi34x3l4xym3p8mlmx"))))
+                "1ndxg7h4xvccjgp5l9z2f8b66dsff6fhf86bn5n7f75a1ksd7554"))))
     (build-system gnu-build-system)
     (propagated-inputs
      `(("flint" ,flint)))               ; flint.h is included by arf.h