netcat: make netcat-openbsd the default netcat (#19411)

The motivation for this change is the following: As gnu-netcat,
e. g. does not support ipv6, it is not suitable as default netcat.

This commit also fixes all obvious build issues caused by this change.

pkgs/desktops/xfce/panel-plugins/xfce4-sensors-plugin.nix

@@ -1,5 +1,5 @@
 { stdenv, fetchurl, pkgconfig, intltool, gnome2, libxfce4ui,
-  libxfce4util, xfce4panel, libnotify, lm_sensors, hddtemp, netcat
+  libxfce4util, xfce4panel, libnotify, lm_sensors, hddtemp, netcat-gnu
 }:
 
 stdenv.mkDerivation rec {
@@ -26,14 +26,14 @@ stdenv.mkDerivation rec {
     libnotify
     lm_sensors
     hddtemp
-    netcat
+    netcat-gnu
    ];
 
   enableParallelBuilding = true;
 
   configureFlags = [
     "--with-pathhddtemp=${hddtemp}/bin/hddtemp"
-    "--with-pathnetcat=${netcat}/bin/netcat"
+    "--with-pathnetcat=${netcat-gnu}/bin/netcat"
   ];
 
   meta = {