JavaScript exception occurs ( call method 'split' of null) if fields have invalid / empty value on the networks page

[Nikolay Fedotov]

ISO: {"build_id": "2013-12-23_00-01-41", "ostf_sha": "2a59b9a850f5c612ef4e8617395a60c27305283f", "build_number": "192", "nailgun_sha": "b6b89d2f145d243a570e86c914a14ab09cd5d84e", "fuelmain_sha": "2e4b3e9b173050def41264feaeeeed47efc9b718", "astute_sha": "a9cb3aad39b0fe9fc8c8399ef6d6e75850a1ed6d", "release": "4.0", "fuellib_sha": "a898b49da10bf5daddb069f60506b65d4c0b2f68"}

*steps*
- create environment
- navigate to networks tab
- clear gateway input or clear both "ip ranges" inputs

*result*
there is no "Invalid value" error near an input
JavaScript exception: Uncaught TypeError: Cannot call method 'split' of undefined utils.js?_=1387807109195:133

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/63768

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/63768
Committed: https://git.openstack.org/cgit/stackforge/fuel-web/commit/?id=32ed0d9cf01a8e25ed32869f1ffc69642a2fa2f4
Submitter: Jenkins
Branch: master

commit 32ed0d9cf01a8e25ed32869f1ffc69642a2fa2f4
Author: jkirnosova <email address hidden>
Date: Mon Dec 23 18:28:23 2013 +0400

    Fixed IP validation

    Closes-Bug: #1263700

    Change-Id: Id9833912b3ce427aaea401d4efea32c46d42d3da