[FIX] mass_mailing: duplicated regex
[FIX] mass_mailing: duplicated regex

laslabs/odoo,bplancher/odoo,Elico-Corp/odoo_OCB,stephen144/odoo,dfang/odoo,microcom/odoo,microcom/odoo,sysadminmatmoz/OCB,sysadminmatmoz/OCB,bplancher/odoo,storm-computers/odoo,bplancher/odoo,hip-odoo/odoo,bplancher/odoo,sysadminmatmoz/OCB,stephen144/odoo,dfang/odoo,Elico-Corp/odoo_OCB,hip-odoo/odoo,sysadminmatmoz/OCB,sysadminmatmoz/OCB,bplancher/odoo,ygol/odoo,microcom/odoo,Elico-Corp/odoo_OCB,ygol/odoo,ygol/odoo,dfang/odoo,hip-odoo/odoo,hip-odoo/odoo,stephen144/odoo,storm-computers/odoo,laslabs/odoo,dfang/odoo,microcom/odoo,sysadminmatmoz/OCB,Elico-Corp/odoo_OCB,laslabs/odoo,ygol/odoo,storm-computers/odoo,storm-computers/odoo,microcom/odoo,dfang/odoo,sysadminmatmoz/OCB,dfang/odoo,stephen144/odoo,ygol/odoo,laslabs/odoo,storm-computers/odoo,Elico-Corp/odoo_OCB,storm-computers/odoo,laslabs/odoo,microcom/odoo,Elico-Corp/odoo_OCB,ygol/odoo,stephen144/odoo,stephen144/odoo,hip-odoo/odoo,hip-odoo/odoo,ygol/odoo,bplancher/odoo,laslabs/odoo