vlan_tag_invalid: change the documentation string

Use a more generic message to permit to use it in other context than VLAN creation.

Signed-off-by: Sebastien Marie <semarie@kapouay.eu.org>

Author: semarie

ocaml/idl/datamodel_errors.ml

@@ -392,8 +392,8 @@ let _ =
 
   error Api_errors.vlan_tag_invalid ["VLAN"]
     ~doc:
-      "You tried to create a VLAN, but the tag you gave was invalid -- it must \
-       be between 0 and 4094. The parameter echoes the VLAN tag you gave."
+      "The VLAN tag you gave was invalid -- it must be between 0 and 4094. The \
+       parameter echoes the VLAN tag you gave."
     () ;
   error Api_errors.network_contains_vif ["vifs"]
     ~doc:"The network contains active VIFs and cannot be deleted." () ;