Unhandled pouchDB promise rejection after this._db.getAttachment

[plarner30]

When loading the tiles from cache sometimes a CustomPouchError can arise after this._db.getAttachment, Error data:

status: 404, name: "not_found", message: "missing", error: true} This causes some tiles to fail to load, around 10% especially around the perimeter of the map after intitial loading.

Not sure if this relates to EPSG basemaps and the issue here: #25. I am having the issue with a UK OS basemap EPSG:3857. I am not using any variable access tokens in the request URLs as far as i can see they are consistent other than the standard &TileMatrix=EPSG:3857:{z}&TileRow={y}&TileCol={x}.

My (temporary) fix is adding a catch block after the this._db.getAttachment promise call and in that firing _onCacheMiss(tile, tileUrl, done); instead.

versions:

"leaflet": "^1.6.0",
"leaflet.tilelayer.pouchdbcached": "^1.0.0",
"pouchdb-browser": "^7.2.2",

Though i have tried with "pouchdb" and fixed to 7.0.0 instead