Fix missing openContents.securityLevel error when unlocking keychain

[stayradiated]

I get this error when I try to unlock the keychain:

/home/stayrad/Git/1pass/lib/contents.js:96
      return this.detail().openContents.securityLevel || 'SL5';
                                       ^
TypeError: Cannot read property 'securityLevel' of undefined
    at Item.Contents.Item.Item.securityLevel (/home/stayrad/Git/1pass/lib/contents.js:96:40)
    at Database.search (/home/stayrad/Git/1pass/lib/database.js:46:32)
    at /home/stayrad/Git/1pass/lib/app.js:58:32
    at /home/stayrad/Git/1pass/lib/app.js:104:20
    at ChildProcess.<anonymous> (/home/stayrad/Git/1pass/lib/password_server.js:27:20)
    at ChildProcess.EventEmitter.emit (events.js:98:17)
    at handleMessage (child_process.js:318:12)
    at Pipe.channel.onread (child_process.js:339:9)

I haven't done much testing, but I'm guessing that one of the items in my keychain doesn't have the openContents property.

A simple fix would be to check that @detail().openContents exists before getting @detail().openContents.securityLevel.

I've run make test and it doesn't seem to cause any issues.