gnu: aegis, quilt: Use file-5.20.

Suggested by Mark H Weaver.

* gnu/packages/version-control.scm (aegis): Use FILE-5.20 instead of FILE.
* gnu/packages/patchutils.scm (quilt): Likewise.

gnu/packages/patchutils.scm

@@ -96,7 +96,7 @@ listing the files modified by a patch.")
     (build-system gnu-build-system)
     (inputs `(("perl" ,perl)
               ("less" ,less)
-              ("file" ,file)
+              ("file" ,file-5.20)                 ;work around CVE-2014-3710
               ("ed" ,ed)))
     (arguments
      '(#:parallel-tests? #f

gnu/packages/version-control.scm

@@ -507,7 +507,7 @@ accessed and migrated on modern systems.")
     (inputs
      `(("e2fsprogs" ,e2fsprogs)
        ("curl" ,curl)
-       ("file" ,file)
+       ("file" ,file-5.20)                        ;work around CVE-2014-3710
        ("libxml2" ,libxml2)
        ("zlib" ,zlib)
        ("gettext" ,gnu-gettext)))