rgw:fix for deleting objects name beginning and ending with underscores of one bucket using POST method of js sdk.
those objects name beginning and ending with underscores can not be deleted using POST method of js sdk
body of http:
#8 Updated by Casey Bodley about 2 years ago
this broke a couple s3tests: s3tests.functional.test_s3.test_versioning_multi_object_delete and test_versioning_multi_object_delete_with_marker
i opened https://github.com/ceph/ceph/pull/12262 to fix, and verified that it also worked with an object named '_key_'