[REM] 4-spaces indent for web view pretty-print-before-save routine

[REM] 4-spaces indent for web view pretty-print-before-save routine

Didn't quite work right: on the layout, it would exponentially increase
leading spaces in text nodes. Combined with a bug injecting snippets marks in
the footer (and thus invalidating and re-saving the layout at each snippet
addition) this could blow up the layout template and rendered page to >20MB.

Just keep lxml's standard 2-spaces indent.

LXML is unable to pretty print the layout anyway.

bzr revid: xmo@openerp.com-20140321075419-9w88h232r928xv5f