Update manifest.yaml (#159)

Didn't test if this was working or not, but I would guess this typo may cause the alert to not appear

manifest.yaml

@@ -62,7 +62,7 @@ volumes:
   compat:
     type: assets
 alerts:
-  intall: Notice! If Bitcoin ever gets stuck in "stopping" status, the solution is to restart your server. System -> Restart.
+  install: Notice! If Bitcoin ever gets stuck in "stopping" status, the solution is to restart your server. System -> Restart.
   uninstall: Uninstalling Bitcoin Core will result in permanent loss of data. Without a backup, any funds stored on your node's default hot wallet will be lost forever. If you are unsure, we recommend making a backup, just to be safe.
   restore: Restoring Bitcoin Core will overwrite its current data. You will lose any transactions recorded in watch-only wallets, and any funds you have received to the hot wallet, since the last backup.
 interfaces: