pruneExpiredApps fails

[ghost]

Describe the bug
* (HEAD detached at 5c378ae4d)

2020-07-23T21:02:20.789Z [TransferService] Start pruneExpiredApps for channel 0x98aa7B68CaC15a08Be1E4C786d6b8e2a53a06685 on chainId 4
2020-07-23T21:02:21.212Z [Main] Unhandled Promise Rejection: TypeError: Cannot read property 'filter' of undefined
    at TransferService.eval (webpack:///./src/transfer/transfer.service.ts?:88:58)
    at Generator.next (<anonymous>)
    at fulfilled (webpack:///./src/transfer/transfer.service.ts?:14:58)
    at runMicrotasks (<anonymous>)
    at processTicksAndRejections (internal/process/task_queues.js:93:5)

[kilrau]

Original PR: #1315

[ArjunBhuptani]

As a note for whoever tackles this: there's nothing actually going wrong here, we just need to not attempt to prune if there are no apps.

[kilrau]

Interesting, but I am pretty sure @erkarl had a pending htlc up there when indra threw the above. Can you add some client logs to confirm? @erkarl

[ghost]

Interesting, but I am pretty sure @erkarl hat a pending htlc up there when indra threw above. Can you add some client logs to confirm? @erkarl

Yup, that was the case on mainnet - got 1 conditional transfer that has expired, but looks like the app was never uninstalled.