Bug#736822: added debug info

[Vlad Orlov]

# sh -x /var/lib/dpkg/info/steam.postrm
+ set -e
+ . /usr/share/debconf/confmodule
+ [ !  ]
+ PERL_DL_NONLAZY=1
+ export PERL_DL_NONLAZY
+ [  ]
+ exec /usr/share/debconf/frontend /var/lib/dpkg/info/steam.postrm
Use of uninitialized value $action in string eq at /usr/share/debconf/frontend line 27.