Ledger related error during startup

[bsclifton]

Test plan

#10113 (comment)

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Getting this while starting up. Can be avoided by checking variable before using

TypeError: Cannot read property 'split' of null
    at ReadStream.v2RulesetDB.createReadStream.on (/Users/clifton/Documents/browser-laptop/app/ledger.js:1401:97)
    at emitOne (events.js:96:13)
    at ReadStream.emit (events.js:191:7)
    at readableAddChunk (/Users/clifton/Documents/browser-laptop/node_modules/level-iterator-stream/node_modules/readable-stream/lib/_stream_readable.js:195:16)
    at ReadStream.Readable.push (/Users/clifton/Documents/browser-laptop/node_modules/level-iterator-stream/node_modules/readable-stream/lib/_stream_readable.js:162:10)
    at /Users/clifton/Documents/browser-laptop/node_modules/level-iterator-stream/index.js:40:12
    at /Users/clifton/Documents/browser-laptop/node_modules/leveldown/node_modules/abstract-leveldown/abstract-iterator.js:24:16
    at /Users/clifton/Documents/browser-laptop/node_modules/leveldown/iterator.js:34:7
    at _combinedTickCallback (internal/process/next_tick.js:73:7)
    at process._tickCallback (internal/process/next_tick.js:104:9)