Checkmk Werk 15632: check_http: Fix Option Enforce IPv4 Properly

ID: 15632 Title: check_http: Fix Option Enforce IPv4 Properly Component: Checks & agents Level: 1 Class: Bug fix Version: 2.3.0b1 In Werk 15621, the behaviour of <tt>Enforce IPv4</tt> was changed. Existing rules have been migrated to a new option (with the old behaviour). However, the selection of the option <tt>Enforce IPv4</tt> in the user interface did not work properly. It resulted in the following crash C+: ValueError('ipv4_enforced' is not a valid Family) C-: This Werk fixes the selection.