Bugfix: Fix force unwraps that lead to crashes

[btxsqdr]

Hey @zjfjack

It can happen that the framework crashes due to too many forceReloads at the same time (2-3x per second), which should not occur, of course, but the framework should also not crash.

Crash root cause are unnecessary force_unwraps. I've tried to remove those, without changing the logic much and causing new issues. The framework is more stable now.

Hint: Technically, there is no reason to use force_unwrap in Swift, except for @IBOutlet or when .dequeueReusableCell() is in use (though it can be avoided for cells). See SwiftLint and coding guidelines by Google, for instance, see https://google.github.io/swift/#force-unwrapping-and-force-casts and also the point about https://google.github.io/swift/#implicitly-unwrapped-optionals

[zjfjack]

I don't think this is necessary.

[btxsqdr]

it was the xcode formatter, apparently. sure, let me remove it.

[zjfjack]

Hi,
Thanks for helping me to improve this project.

Can you remove all the indents change from SwiftLint in this pull request? I think it is really confused in this pull request. If it is necessary, I will apply SwiftLint in another day and remove all the indents in this project in one commit.

Thanks again

[zjfjack]

Hi,

In order to improve this project, I applied Swiftlint and update to Swift 5. Could you rebase the master branch and push again?

Thanks