Bug 35352: Allow SMSalertnumber to be hidden via BorrowerUnwantedField

Bug 35352: Allow SMSalertnumber to be hidden via BorrowerUnwantedField

To test:
1. Add a value to SMSSendDriver like 'Emial'.
2. Go to BorrowerUnwantedField and attempt to hide "Mobile phone number (smsalertnumber)"
3. Go to members/memberentry.pl and see the field is not hidden.
4. APPLY PATCH
5. Try step 3 again and this time the field should be properly hidden.

Note: This patch also includes some indentation changes.
Signed-off-by: Andrew Fuerste-Henry <andrewfh@dubcolib.org>
Signed-off-by: Victor Grousset/tuxayo <victor@tuxayo.net>
Signed-off-by: Katrin Fischer <katrin.fischer@bsz-bw.de>
(cherry picked from commit 6aa971be01987e041dcb55a71ad2f36e3f2c40d1)
Signed-off-by: Fridolin Somers <fridolin.somers@biblibre.com>