rgw: add release note for newly-quoted ETag values

Signed-off-by: Casey Bodley <[email protected]>

Author: cbodley

PendingReleaseNotes

@@ -16,6 +16,8 @@
   moving backwards as a result.
 * RGW: IAM policy evaluation now supports conditions ArnEquals and ArnLike, along
   with their Not and IfExists variants.
+* RGW: Adding missing quotes to the ETag values returned by S3 CopyPart,
+  PostObject and CompleteMultipartUpload responses.
 
 * RBD: All Python APIs that produce timestamps now return "aware" `datetime`
   objects instead of "naive" ones (i.e. those including time zone information