The network admin email setting for a network is often used as a catch-all or notification email separate from the actual user ID set as the owner of the new network. If a non-user email address is set during network installation, we can defer to the current user as the actual network admin and apply the entered email as the address to which general notifications are sent and emails are sent from.
In the future, we'll want to update the messaging around "Network Admin Email" to reflect its reality. See #34293.
Props jjeaton.
Fixes#34065.
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