Remove "Login Label" from Account settings
Remove "Login Label" from Account settings

Closes USERS-109
flag=none

Per the ticket, this field is deprecated on this screen
and instead appears in the Authentication settings.

Test plan:
* The field is gone from /accounts/:id/settings

Change-Id: I4ccd0961cc10d9d77651d521a89e8a09bc422774
Reviewed-on: https://gerrit.instructure.com/c/canvas-lms/+/220042
Tested-by: Service Cloud Jenkins <9144042a601061f88f1e1d7a1753ea3e2972119d@instructure.com>
Tested-by: Jenkins
QA-Review: Steve Shepherd <e794458448443812fb2685675aab3bbd1a3891bc@instructure.com>
Product-Review: Charley Kline <05950d7e90ba5e3da323378368c22b3ffaaf6647@instructure.com>
Reviewed-by: Landon Gilbert-Bland <60d9ff23682c863d36b48b4c32c5ce5f434d29c0@instructure.com>

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