fix: change function order

[p0lycarpio]

Related to #1104 (comment).

Indeed @billz , the order of the functions produces these errors.
Restoring original order in this PR.

[p0lycarpio]

Restoring the function to its original order no longer saves the raspap.auth file during an upgrade.
It is necessary to investigate

[p0lycarpio]

1f9638c Reversal of priority of functions in the event of an upgrade.

Explanations:
In the event of an upgrade, the backup of the raspap.auth file must be done in priority with _check_for_old_configs , before launching the _check_for_old_configs function which moves the raspap folder (and raspap.auth) to make a backup.

There may be another way to do this thing but it works for me. Please confirm it to me

[billz]

To keep things neater, I'd opt for a solution that doesn't use conditionals in the main _install_raspap() function block.

[billz]

Fixed with 9d5088a. @p0lycarpio thanks