[fix] rare problem with o2m & buttons
[fix] rare problem with o2m & buttons

MarkusTeufelberger/openerp-web,splbio/openerp-web,gisce/openerp-web,gisce/openerp-web,MarkusTeufelberger/openerp-web,gisce/openerp-web,splbio/openerp-web,splbio/openerp-web,MarkusTeufelberger/openerp-web