search by blog id under ms-sites.php uses the wrong parameter

[Denis-de-Bernardy]

it's using intval of the search string instead of the blog id.

[Denis-de-Bernardy]

the case for non-numerical data is not covered in the above patch, and can lead to a division by zero further down if used because of ceil($total / $num).

[Denis-de-Bernardy]

that second remark was for #11786.

this one can go straight in.

[ryan]

[12639]