[FIX] ir_attachment: typo introduced in previous fix (3319) (backport of trunk)
[FIX] ir_attachment: typo introduced in previous fix (3319) (backport of trunk)

Original revision: 3319 - olt@tinyerp.com-20110125142329-x1sf2qlazfiy6bdw
The consequence is that access rights on attachments would be incorrectly checked, using the
intersection of the attachment IDs and the resource IDs.
ovnicraft/openerp-server,vnc-biz/openerp-server,gisce/openobject-server,splbio/openobject-server,splbio/openobject-server,vnc-biz/openerp-server,ovnicraft/openerp-server,gisce/openobject-server,splbio/openobject-server,MarkusTeufelberger/openobject-server,MarkusTeufelberger/openobject-server,gisce/openobject-server,MarkusTeufelberger/openobject-server