Bug#1102356: hx: BSD-3-clause references different license

[Bastian Germann]

Source: hx
Version: 25.01.1-4
Severity: important

The BSD-3-clause stanza in debian/copyright refers to
/usr/share/common-licenses/BSD, which has a slightly different than the
actual helix-view/tests/encoding/LICENSE-WHATWG. Please copy the license
text.