storage/pruning: light node on mocha-4 is not pruning historical data

[Bidon15]

Celestia Node version

v0.13.0

OS

macOS

Install tools

1. clone repo
2. checkout v0.12.4
3. run binary
4. checkout later at v0.13.0

Others

No response

Steps to reproduce it

1. Install v0.12.4
2. Initialise a da light node for mocha-4 testnet
3. Sync to 1100000 block height
4. Install v0.13.0
5. Sync a v0.13.0 light node to the tip of the chain

Expected result

Pruning is done to historical blocks

Actual result

Pruning is not done for historical blocks. Light node is still storing past recency window data

Relevant log output

du -h ~/.celestia-light-mocha-4/
8.0K	/Users/bidon4/.celestia-light-mocha-4//keys/keyring-test
 16K	/Users/bidon4/.celestia-light-mocha-4//keys
 23G	/Users/bidon4/.celestia-light-mocha-4//data
 32G	/Users/bidon4/.celestia-light-mocha-4/

Notes

This is an acceptance test for users of da light nodes that are migrating from v0.12.4 to latest v0.13.0