ORM: fix bug at orm.copy_data(), would reset context[lang]
ORM: fix bug at orm.copy_data(), would reset context[lang]

Thanks to Dr. Gassauer that made me revise this code.

ovnicraft/openerp-server,MarkusTeufelberger/openobject-server,gisce/openobject-server,gisce/openobject-server,splbio/openobject-server,splbio/openobject-server,MarkusTeufelberger/openobject-server,vnc-biz/openerp-server,ovnicraft/openerp-server,splbio/openobject-server,gisce/openobject-server,vnc-biz/openerp-server,MarkusTeufelberger/openobject-server