libpcap: 1.9.0 -> 1.9.1 (security!)

http://www.tcpdump.org/libpcap-changes.txt

> Five CVE-2019-15161, CVE-2019-15162, CVE-2019-15163, CVE-2019-15164, CVE-2019-15165
> Fixes for CVE-2018-16301,

Drop the included patch as well.

pkgs/development/libraries/libpcap/default.nix

@@ -1,11 +1,12 @@
-{ stdenv, fetchurl, fetchpatch, flex, bison }:
+{ stdenv, fetchurl, flex, bison }:
 
 stdenv.mkDerivation rec {
-  name = "libpcap-1.9.0";
+  pname = "libpcap";
+  version = "1.9.1";
 
   src = fetchurl {
-    url = "https://www.tcpdump.org/release/${name}.tar.gz";
-    sha256 = "06bhydl4vr4z9c3vahl76f2j96z1fbrcl7wwismgs4sris08inrf";
+    url = "https://www.tcpdump.org/release/${pname}-${version}.tar.gz";
+    sha256 = "153h1378diqyc27jjgz6gg5nxmb4ddk006d9xg69nqavgiikflk3";
   };
 
   nativeBuildInputs = [ flex bison ];
@@ -27,15 +28,6 @@ stdenv.mkDerivation rec {
     substituteInPlace configure --replace " -arch i386" ""
   '';
 
-  patches = [
-    # https://github.com/the-tcpdump-group/libpcap/pull/735
-    (fetchpatch {
-      name = "add-missing-limits-h-include-pr735.patch";
-      url = https://github.com/the-tcpdump-group/libpcap/commit/aafa3512b7b742f5e66a5543e41974cc5e7eebfa.patch;
-      sha256 = "05zb4hx9g24gx07bi02rprk2rn7fdc1ss3249dv5x36qkasnfhvf";
-    })
-  ];
-
   meta = with stdenv.lib; {
     homepage = https://www.tcpdump.org;
     description = "Packet Capture Library";