gnu: js-filesaver: Don't use unstable tarball.

* gnu/packages/javascript.scm (js-filesaver)[source]: Use 'git-fetch'.

gnu/packages/javascript.scm

@@ -386,13 +386,14 @@ means that these shams cause many ES5 methods to silently fail.")
     (name "js-filesaver")
     (version "1.3.8")
     (source (origin
-              (method url-fetch)
+              (method git-fetch)
-              (uri (string-append "https://github.com/eligrey/FileSaver.js/"
+              (uri (git-reference
-                                  "archive/" version ".tar.gz"))
+                     (url "https://github.com/eligrey/FileSaver.js")
-              (file-name (string-append name "-" version))
+                     (commit version)))
+              (file-name (git-file-name name version))
               (sha256
                (base32
-                "1rkhfqs5plaj628kzj7qgm5qahy4v7ihygifidqr6g6265mil97h"))))
+                "0gvqk0hnr8fig0n4da7vj7q6z31bcyv52916xz3rbmdj3pgpiv1d"))))
     (build-system minify-build-system)
     (arguments
      `(#:phases