testing/seaweedfs: upgrade to 2.87

S3

Bucket Quota Management

Mount

Better support for large file random writes. 
Use swap file instead of all buffered in memory. 
Reduce memory consumption. 
Avoids IO corruption during Sqlite vaccum.

Filer

Deduplicate metadata events during retries.
Cassandra filer store adds connection timeout option.

Master

Adds metrics port for Prometheus.