jmap: fix crash when opening multiple instances

Fix the following error when opening another aerc instance with the same
jmap account:

panic: runtime error: invalid memory address or nil pointer dereference
[signal SIGSEGV: segmentation violation code=0x1 addr=0x8 pc=0x9a1ffd]

git.sr.ht/~rjarry/aerc/worker/jmap/cache.(*JMAPCache).get(0x99d08e?, {0xbc3c1a?, 0xc00003a160?})
	git.sr.ht/~rjarry/aerc/worker/jmap/cache/cache.go:47 +0x1d
git.sr.ht/~rjarry/aerc/worker/jmap/cache.(*JMAPCache).GetSession(0xc00052a030?)
	git.sr.ht/~rjarry/aerc/worker/jmap/cache/session.go:8 +0x29
git.sr.ht/~rjarry/aerc/worker/jmap.(*JMAPWorker).handleConnect(0xc00055e180, 0x0?)
	git.sr.ht/~rjarry/aerc/worker/jmap/connect.go:29 +0xd3
git.sr.ht/~rjarry/aerc/worker/jmap.(*JMAPWorker).handleMessage(0xc000311500?, {0xcc8b00?, 0xc0001fcff0?})
	git.sr.ht/~rjarry/aerc/worker/jmap/worker.go:114 +0x9f
git.sr.ht/~rjarry/aerc/worker/jmap.(*JMAPWorker).Run(0xc00055e180)
	git.sr.ht/~rjarry/aerc/worker/jmap/worker.go:177 +0x10c
git.sr.ht/~rjarry/aerc/widgets.NewAccountView.func3()
	git.sr.ht/~rjarry/aerc/widgets/account.go:110 +0x65
created by git.sr.ht/~rjarry/aerc/widgets.NewAccountView
	git.sr.ht/~rjarry/aerc/widgets/account.go:103 +0x518

Do not return an error if the leveldb cannot be opened, log a message
and fallback on the in-memory cache.

Fixes: be0bfc1ae28b ("worker: add jmap support")
Reported-by: Tim Culverhouse <tim@timculverhouse.com>
Signed-off-by: Robin Jarry <robin@jarry.cc>
Tested-by: Tim Culverhouse <tim@timculverhouse.com>

0 files changed, 0 insertions, 0 deletions