gnugrep: Update to 2.20

pkgs/tools/text/gnugrep/default.nix

@@ -1,21 +1,18 @@
-{ stdenv, fetchurl, pcre, libiconv ? null }:
+{ stdenv, fetchurl, pcre, libiconvOrNull }:
 
-let version = "2.14"; in
+let version = "2.20"; in
 
 stdenv.mkDerivation {
   name = "gnugrep-${version}";
 
   src = fetchurl {
     url = "mirror://gnu/grep/grep-${version}.tar.xz";
-    sha256 = "1qbjb1l7f9blckc5pqy8jlf6482hpx4awn2acmhyf5mv9wfq03p7";
+    sha256 = "0rcs0spsxdmh6yz8y4frkqp6f5iw19mdbdl9s2v6956hq0mlbbzh";
   };
 
-  buildInputs = [ pcre ]
-    ++ stdenv.lib.optional (libiconv != null) libiconv;
+  buildInputs = [ pcre libiconvOrNull ];
 
-  patches = [ ./test-localeconv.patch ];
-
-  NIX_LDFLAGS = stdenv.lib.optionalString (libiconv != null) "-L${libiconv}/lib -liconv";
+  NIX_LDFLAGS = stdenv.lib.optionalString (libiconvOrNull != null) "-L${libiconvOrNull}/lib -liconv";
 
   doCheck = !stdenv.isDarwin;
 
@@ -37,7 +34,7 @@ stdenv.mkDerivation {
 
     license = stdenv.lib.licenses.gpl3Plus;
 
-    maintainers = [ ];
+    maintainers = [ stdenv.lib.maintainers.eelco ];
     platforms = stdenv.lib.platforms.all;
   };