Bucket delete is not cleaning up secondary indexes

This is a regression. Automated test: TestBucketDefaultDelete

This was tested on unstable upto 72837aedd0f2186ac5d18975f28617eb15e6bafd

Manual repro steps:
1. Create a bucket, sample beer-sample
2. Create a 2i on the bucket
3. Delete bucket
4. List the indexes - the index still appears as active.

From indexer logs:
15:21:53.230189 [Error] Indexer::getCurrentKVTs Error Connecting to KV Cluster No bucket named beer-sample
15:21:53.230203 [Error] Timekeeper::handleStats Error occured while obtaining KV seqnos - No bucket named beer-sample
15:21:54.231771 [Error] Indexer::getCurrentKVTs Error Connecting to KV Cluster No bucket named beer-sample
15:21:54.231780 [Error] Timekeeper::handleStats Error occured while obtaining KV seqnos - No bucket named beer-sample
15:21:55.227567 [Error] Indexer::getCurrentKVTs Error Connecting to KV Cluster No bucket named beer-sample
15:21:55.227574 [Error] Timekeeper::handleStats Error occured while obtaining KV seqnos - No bucket named beer-sample
15:21:56.228769 [Error] Indexer::getCurrentKVTs Error Connecting to KV Cluster No bucket named beer-sample
15:21:56.228779 [Error] Timekeeper::handleStats Error occured while obtaining KV seqnos - No bucket named beer-sample
15:21:57.228139 [Error] Indexer::getCurrentKVTs Error Connecting to KV Cluster No bucket named beer-sample

Logs attached for bucket beer-sample