Change Jetpack connection delegates to weak references

[crazytonyli]

Relates to #21050.

The changed delegate properties should be declared as weak references, considering how they are used:

WordPress-iOS/WordPress/Classes/ViewRelated/Jetpack/Login/JetpackLoginViewController.swift

Lines 170 to 176 in 3d8c016

	fileprivate func openInstallJetpackURL() {
	trackStat(.selectedInstallJetpack)
	let controller = JetpackConnectionWebViewController(blog: blog)
	controller.delegate = self
	let navController = UINavigationController(rootViewController: controller)
	present(navController, animated: true)
	}

WordPress-iOS/WordPress/Classes/ViewRelated/Jetpack/Install/JetpackRemoteInstallViewController.swift

Lines 104 to 110 in 3d8c016

	func openInstallJetpackURL() {
	viewModel.track(AccountHelper.isLoggedIn ? .connect : .login)
	let controller = JetpackConnectionWebViewController(blog: blog)
	controller.delegate = self
	navigationController?.pushViewController(controller, animated: true)
	}

Regression Notes

1. Potential unintended areas of impact
   None.

2. What I did to test those areas of impact (or what existing automated tests I relied on)
   None.

3. What automated tests I added (or what prevented me from doing so)
   None.

PR submission checklist:

• I have completed the Regression Notes.
• I have considered adding unit tests for my changes.
• I have considered adding accessibility improvements for my changes.
• I have considered if this change warrants user-facing release notes and have added them to RELEASE-NOTES.txt if necessary.

UI Changes testing checklist: N/A

[wpmobilebot]

📲 You can test the changes from this Pull Request in Jetpack Alpha by scanning the QR code below to install the corresponding build.

	App Name	Jetpack Alpha
	Configuration	Release-Alpha
	Build Number	pr21052-22389b1
	Version	22.8
	Bundle ID	com.jetpack.alpha
	Commit	22389b1
	App Center Build	jetpack-installable-builds #5426

Automatticians: You can use our internal self-serve MC tool to give yourself access to App Center if needed.

[wpmobilebot]

📲 You can test the changes from this Pull Request in WordPress Alpha by scanning the QR code below to install the corresponding build.

	App Name	WordPress Alpha
	Configuration	Release-Alpha
	Build Number	pr21052-22389b1
	Version	22.8
	Bundle ID	org.wordpress.alpha
	Commit	22389b1
	App Center Build	WPiOS - One-Offs #6399

Automatticians: You can use our internal self-serve MC tool to give yourself access to App Center if needed.