[FIX] packaging: include favicon

missing .ico files

Fixes #7745

MANIFEST.in

@@ -5,6 +5,7 @@ recursive-include openerp *.css
 recursive-include openerp *.csv
 recursive-include openerp *.gif
 recursive-include openerp *.html
+recursive-include openerp *.ico
 recursive-include openerp *.jpeg
 recursive-include openerp *.jpg
 recursive-include openerp *.js