s3fs 7.x-2.9

Issue #2853778 by jansete: Config form does not display region "EU - London (eu-west-2)"
Issue #2821971 by prince_zyxware, jansete: Fix coding standard - spacing issues
Issue #2851983: Removed the largely pointless cache for s3fs_file table reads.
Issue #2858314: Corrected rmdir()'s improper SQL queries.

Replaced/removed the old s3fs_use_instance_profile var.
The new database update removes the VERY old s3fs_use_instance_profile variable, saving it's value (if set) into s3fs_awssdk2_use_instance_profile.
Now, only the s3fs_awssdk2_use_instance_profile variable and awssdk2_use_instance_profile settings.php override are used.

BACKWARD INCOMPATIBILITY:
Because s3fs no longer reads the s3fs_use_instance_profile variable, those who hard-coded it into settings.php will need to change

$conf['s3fs_use_instance_profile'] = TRUE;

to:

$conf['awssdk2_use_instance_profile'] = TRUE;

If you did not hard-code s3fs_use_instance_profile into settings.php, this update IS backwards compatible.