Before this commit the bootstrap version we used was inconsistent.
Indeed, the javascript files were the 3.3.4 ones and the less files
were the 3.3.5 ones. This was due to a failed merged resolution in 9.0.
This should however not cause any issue as the difference between
3.3.x versions are very minor.
Basically, this commit is more of a fix than an improvement and may
even be backported if we find reasons to do so. This commit is mainly
made to prepare the transition to version 4.0.0, which requires to
switch our LESS files to SCSS first (and it will be easier to go by
bootstrap 3.3.7 with SCSS files first).
qsm-odoo