devpi-client: fix build

Upstream has already patched this, but haven't done a release yet.
185072fcc6

pkgs/development/tools/devpi-client/default.nix

@@ -32,6 +32,12 @@ buildPythonApplication rec {
     sha256 = "24ac6d94108996efad4ff5185dabb1e5120ae238134b8175d6de2ca9e766cd92";
   };
 
+  postPatch = ''
+    # can be removed after 5.2.2, updated upstream
+    substituteInPlace setup.py \
+      --replace "pluggy>=0.6.0,<1.0" "pluggy"
+  '';
+
   buildInputs = [ glibcLocales ];
 
   propagatedBuildInputs = [ py devpi-common pluggy setuptools check-manifest pkginfo ];