./configure requires another linker argument

[madthanu]

Phoeagon reports that the alice-strace tool requires another linker argument, when compiling in 32-bit Ubuntu. Phoeagon already provided a quick fix: kisslab@7f03eba . Given that I have zero-knowledge about the configure script, if someone would review phoeagon's fix (may be even phoeagon himself), that would be very appreciated.

However, since the "configure" script in the tree is actually generated (on a 64-bit machine) and slightly customized from "configure.ac" of strace-plus (https://code.google.com/p/strace-plus/source/browse/), dabbling with the "configure" script is not the "proper" fix. The proper way would be to pull the "configure.ac" script from strace-plus, and customize it to so that libunwind is mandatory (strace-plus makes libunwind optional). I will again leave it to more brainy people to do that fix, too.