Update FirefoxNightly-79.0a1 -> 81.0a1. (#3142)

* Update firefoxnightly-79.0a1 -> 81.0a1.
firefoxnightly-79.0a1 url is not valid anymore. Update is necessary.

* Fix hash.

* Fix hash for new release.

* Fix hash for new release. (Release Date: 20-Aug-2020 23:18)

* Fix hash for new release. (Release Date: 21-Aug-2020 10:20)

manifests/Mozilla/FirefoxNightly/81.0a1.yaml

@@ -1,23 +1,18 @@
-# ================== General ==================
-
 Id: Mozilla.FirefoxNightly
-Publisher: Mozilla
+Version: 81.0a1
 Name: Firefox Nightly
+Publisher: Mozilla
+License: Mozilla Public License V2.0
+LicenseUrl: https://www.mozilla.org/en-US/MPL/2.0/
 AppMoniker: firefox-nightly
+Tags: firefox, browser, mozilla, nighly
 Description: "Get a sneak peek at our next generation web browser, and help us make it the best browser it can be: try Firefox Nightly."
 Homepage: https://www.mozilla.org/en-US/firefox/nightly/
-Tags: Browser, Mozilla, Firefox, Nightly
-License: Mozilla Public License Version 2.0
-LicenseUrl: https://www.mozilla.org/en-US/MPL/2.0/
-
-# ================= Installer =================
-
-Version: 79.0a1
-
-InstallerType: msi
 Installers:
   - Arch: x64
-    Url: https://download-installer.cdn.mozilla.net/pub/firefox/nightly/latest-mozilla-central/firefox-79.0a1.en-US.win64.installer.msi
-    Sha256: 1DB02121574E0D2253E00E06AA50B5FC60FF33BC7304BD87D619F69DE60D8884
-
-# Auto Generated by softcreatr@winget.it on Tue, 09 Jun 2020 16:38:06 +0000
+    Url: https://download-installer.cdn.mozilla.net/pub/firefox/nightly/latest-mozilla-central/firefox-81.0a1.en-US.win64.installer.msi
+    Sha256: EFEB7AA91AFB6FCF2DA01F1975A05C0B3775DED991A2E3CDB2572D4F660A840F
+    InstallerType: msi
+    Switches:
+      Silent: /quiet /norestart
+      SilentWithProgress: /passive /norestart