OperationalError: cannot commit - no transaction is active in core/src/Db/Db.py line 169 (reason: Interval)

### Step 1: Please describe your environment

* ZeroNet version: r4404
* Operating system: W10
* Web browser: FF beta
* Tor status: error
* Opened port: no

### Step 2: Describe the problem:

debug.log shows:

ERROR Db#0:Chart Commit error: OperationalError: cannot commit - no transaction is active in core/src/Db/Db.py line 169 (reason: Interval)

on restart it not appeared, then i quit and start again and appeared again.

Start by reading core/src/Db/Db.py around line 169 and inspect the debug.log entry for the Chart commit error. Reproduce the reported quit-and-restart sequence if possible, then determine whether the interval-related path still attempts a commit without an active transaction. Done means the reported error no longer appears during the described restart flow.

索引モデルが issue の本文から書いたものです。