WebUI: reword OTP info message displayed during PW reset
The message displayed before is now limited to the OTP
sync form, for which it was written originally.
A new message is introduced for the PW reset form,
which clarifies the usage of the OTP field.
Fixes: https://pagure.io/freeipa/issue/5628
Reviewed-By: Alexander Bokovoy <abokovoy@redhat.com>