xpra: 2.5 -> 2.5.3

Also fix build by using opencv4

pkgs/tools/X11/xpra/default.nix

@@ -14,11 +14,11 @@ let
   xf86videodummy = callPackage ./xf86videodummy { };
 in buildPythonApplication rec {
   pname = "xpra";
-  version = "2.5";
+  version = "2.5.3";
 
   src = fetchurl {
     url = "https://xpra.org/src/${pname}-${version}.tar.xz";
-    sha256 = "0q6c7ijgpp2wk6jlh0pzqki1w60i36wyl2zfwkg0gpdh40ypab3x";
+    sha256 = "1ys35lj28903alccks9p055psy1fsk1nxi8ncchvw8bfxkkkvbys";
   };
 
   patches = [
@@ -56,7 +56,7 @@ in buildPythonApplication rec {
   propagatedBuildInputs = with python3.pkgs; [
     pillow rencode pycrypto cryptography pycups lz4 dbus-python
     netifaces numpy pygobject3 pycairo gst-python pam
-    pyopengl paramiko opencv python-uinput pyxdg
+    pyopengl paramiko opencv4 python-uinput pyxdg
     ipaddress idna
   ];