Bug#962251: hugin: libboost-signals-dev no longer exists with boost1.71

[Adrian Bunk]

Source: hugin
Version: 2019.2.0+dfsg-1
Severity: serious
Tags: ftbfs
Control: block 961995 by -1

https://buildd.debian.org/status/package.php?p=hugin

libboost-signals-dev no longer exists with boost1.71.