Bug 16213: (QA follow-up) Fix terminology

Signed-off-by: Josef Moravec <josef.moravec@gmail.com>

Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>

api/v1/swagger/paths/holds.json

@@ -192,7 +192,7 @@
                 "format": "date"
               },
               "itemtype": {
-                "description": "Limit reserve on one itemtype (ignored for item-level holds)",
+                "description": "Limit hold on one itemtype (ignored for item-level holds)",
                 "type": "string"
               }
             }