Create bucket with REST API fails on port 11211

Summary: Creating a bucket with the REST API doesn't work when there are no buckets and when using proxyPort 11211. This was reported on Twitter: https://twitter.com/Ocramius/status/935636070045310977

Repro:

curl -v -u Administrator:password \ -X POST http://127.0.0.1:8091/pools/default/buckets \ -d 'bucketType=couchbase' \ -d 'name=default' \ -d 'ramQuotaMB=300' \ -d 'authType=none' \ -d 'proxyPort=11211'

Does not create a bucket, but the following does:

curl -v -u Administrator:password \ -X POST http://127.0.0.1:8091/pools/default/buckets \ -d 'bucketType=couchbase' \ -d 'name=default' \ -d 'ramQuotaMB=300' \ -d 'authType=none' \ -d 'proxyPort=11400'

Notes:

If this isn't a bug, then it's probably a documentation issue, so please assign it to the doc team.