greetd.nix: fix session escaping

modules/services/greetd.nix

@@ -37,12 +37,12 @@ in {
       settings.default_session = {
         command = ''
           ${pkgs.greetd.tuigreet}/bin/tuigreet \
-            -c '${cfg.session}' \
+            -c \"${cfg.session}\" \
             -r 
             -t --time-format "DD.MM.YYYY"
             --asteriks'';
       };
-      vt = 1;
+      vt = 7;
     };
   };
 }