Fix translation.

i18n/en.i18n.json

@@ -600,8 +600,8 @@
     "r-d-add-member": "Add member",
     "r-d-remove-member": "Remove member",
     "r-d-remove-all-member": "Remove all member",
-    "r-d-check-all": "Check all items of list",
+    "r-d-check-all": "Check all items of a list",
-    "r-d-uncheck-all": "Uncheck all items of list",
+    "r-d-uncheck-all": "Uncheck all items of a list",
     "r-d-check-one": "Check item",
     "r-d-uncheck-one": "Uncheck item",
     "r-d-check-of-list": "of checklist",