fix citus install phase

Author: steve-chavez

ext/citus.nix

@@ -16,9 +16,13 @@ stdenv.mkDerivation rec {
   installPhase = ''
     mkdir -p $out/{lib,share/postgresql/extension}
 
-    cp *.so      $out/lib
-    cp *.sql     $out/share/postgresql/extension
-    cp *.control $out/share/postgresql/extension
+    cp src/backend/columnar/citus_columnar.so      $out/lib
+    cp src/backend/columnar/citus_columnar.control $out/share/postgresql/extension
+    cp src/backend/columnar/build/sql/*.sql        $out/share/postgresql/extension
+
+    cp src/backend/distributed/citus.so            $out/lib
+    cp src/backend/distributed/citus.control       $out/share/postgresql/extension
+    cp src/backend/distributed/build/sql/*.sql     $out/share/postgresql/extension
   '';
 
   meta = with lib; {