Site Health: don't give a warning when upload_max_size is lower than max_post_size

[jeroenrotty]

Site Health component added a new check in version 5.5 where post_max_size differs from upload_max_size which can lead to upload issues.

However, there is no need to show a warning/error if post_max_size is a higher value than upload_max_size. In a current site I maintain, post_max_size is 8M and the max_upload_size is 2M and the Improvement is shown.

Also, the copy might need to be reviewed, as we literally say that the values differ and *that* is the issue.

[desrosj]

Introduced in [48535] and adjusted in [48538-48539,48544] (see #50038).

[Clorith]

#51032 was marked as a duplicate.

[Clorith]

The attached patch in 50945.diff​ is spot on, and makes this report much more accurate.

[SergeyBiryukov]

In 48800:

Site Health: Only display the warning about the post_max_size PHP value when it's lower than upload_max_filesize.

Previously, the warning was displayed even if the value was higher than upload_max_filesize, which made the report inaccurate, as these values don't necessarily have to match.

Props oakesjosh, jeroenrotty, desrosj, Clorith.
Fixes #50945.

[SergeyBiryukov]

In 48801:

Site Health: Rename the $upload_max_size variable to $upload_max_filesize, for consistency with the PHP setting name.

Follow-up to [48535], [48538], [48539], [48544], [48800].

See #50945.

[SergeyBiryukov]

Reopening for the 5.5 branch.

[SergeyBiryukov]

In 48806:

Site Health: Only display the warning about the post_max_size PHP value when it's lower than upload_max_filesize.

Previously, the warning was displayed even if the value was higher than upload_max_filesize, which made the report inaccurate, as these values don't necessarily have to match.

Props oakesjosh, jeroenrotty, desrosj, Clorith.
Merges [48800] and [48801] to the 5.5 branch.
Fixes #50945.