[FIX] make empty readonly fields not look like empty writable field

bzr revid: xmo@openerp.com-20111214131246-x3t2l4u5in1gwyp4

diff --cc addons/web/static/src/css/base.css
index 4badc4d,f0bdc87..04fff6c
--- 1/addons/web/static/src/css/base.css
--- 2/addons/web/static/src/css/base.css
+++ b/addons/web/static/src/css/base.css
@@@ -1150,7 -1151,9 +1150,11 @@@ label.error 
  .openerp .oe_forms select{
      padding-top: 2px;
  }
- 
 -.openerp .oe_forms input[disabled],.openerp .oe_forms select[disabled], .openerp .oe_forms textarea[disabled]{
++.openerp .oe_forms input[disabled],
++.openerp .oe_forms select[disabled],
++.openerp .oe_forms textarea[disabled]{
+     background: #E0E0E0;
+ }
  .openerp .oe_forms textarea {
      resize:vertical;
  }