net-mgmt/py-ciscoconfparse: Update to 1.4.3

• Add "do-test" target to make future QA easier

Changelog since 1.3.43:

• Add parser for various NXOS features
• Fix issue with "ip_helper_adddresses" function that wasn't able to handle 'global' helpers
• Implement "re_search_children()" directly on the "CiscoConfParse()" object
• Fix NXOS HRSP issue with "has_ip_hsrp" function