Bug 12223 - members-update.tt has misspelled field B_phone name

Bug 12223 - members-update.tt has misspelled field B_phone name

This patch fixes a misspelled word

To test:
1. login in opac, clic personal details, change Alternate phone
number and submit
2. go to staff, Patrons, clic on link 'Patrons requesting modifications'
Alternate phone has mispelled label
3. apply the patch
4. reload, label is fixed

Followed test plan. Typo is fixed.
Signed-off-by: Marc Véron <veron@veron.ch>
Signed-off-by: Katrin Fischer <Katrin.Fischer.83@web.de>
Fixes a typo, no problems found.

Signed-off-by: Tomas Cohen Arazi <tomascohen@gmail.com>