[FIX] reports: allow empty images with reportlab 2.5
[FIX] reports: allow empty images with reportlab 2.5
MarkusTeufelberger/openobject-server,MarkusTeufelberger/openobject-server,MarkusTeufelberger/openobject-server,ovnicraft/openerp-server,gisce/openobject-server,vnc-biz/openerp-server,splbio/openobject-server,splbio/openobject-server,gisce/openobject-server,ovnicraft/openerp-server,vnc-biz/openerp-server,splbio/openobject-server,gisce/openobject-server