[FIX] report: use hardcoded viewport in wkhtmltopdf to use col-md-* Bootstrap

Without this, wkhtmltopdf, don't use media query from bootstrap and so respect
only col-xs-* class (xs by default because no media query).

Viewport from wkhtmltopdf is not really respected, so 1024x768 or 1920x768 will
not change the real view port, but only use the right media query.

addons/report/models/report.py

@@ -375,6 +375,8 @@ class Report(osv.Model):
         :returns: Content of the pdf as a string
         """
         command_args = []
+        if wkhtmltopdf_state == "ok":
+            command_args.extend(['--viewport-size', '1024x768'])
 
         # Passing the cookie to wkhtmltopdf in order to resolve internal links.
         try: