Checkmk Werk 15621: <tt>check_http</tt>: Fix Option <tt>Enforce IPv4</tt>

ID: 15621 Title: <tt>check_http</tt>: Fix Option <tt>Enforce IPv4</tt> Component: Checks & agents Level: 1 Class: Bug fix Version: 2.3.0b1 The option <tt>Enforce IPv4</tt> of the rule <tt>Check HTTP service</tt> did not enforce IPv4. With this Werk, <tt>Enforce IPv4</tt> adds the option '-4' to the service check command. Existing rules are migrated to the new option <tt>Use any network address</tt>. Thus, their behaviour does not change.