Update git submodules

* Update swift from branch 'master'
  - Merge "ratelimit: Allow multiple placements"
  - ratelimit: Allow multiple placements
    
    We usually want to have ratelimit fairly far left in the pipeline -- the
    assumption is that something like an auth check will be fairly expensive
    and we should try to shield the auth system so it doesn't melt under the
    load of a misbehaved swift client.
    
    But with S3 requests, we can't know the account/container that a request
    is destined for until *after* auth. Fortunately, we've already got some
    code to make s3api play well with ratelimit.
    
    So, let's have our cake and eat it, too: allow operators to place
    ratelimit once, before auth, for swift requests and again, after auth,
    for s3api. They'll both use the same memcached keys (so users can't
    switch APIs to effectively double their limit), but still only have each
    S3 request counted against the limit once.
    
    Change-Id: If003bb43f39427fe47a0f5a01dbcc19e1b3b67ef

swift

@@ -1 +1 @@
-Subproject commit ede9dad9f6e56831f3068c805cdd61dbb3fac7c0
+Subproject commit 6c1bc3949d74477706bc2258a45a603d3bfc236c