setup.py: Fix dash to be ASCII so pip doesn't complain.

setup.py

@@ -48,7 +48,7 @@ Boost.Python library by David Abrahams: to minimize boilerplate code in
 traditional extension modules by inferring type information using compile-time
 traditional extension modules by inferring type information using compile-time
 introspection.
 introspection.
 
 
-The main issue with Boost.Python—and the reason for creating such a similar
+The main issue with Boost.Python-and the reason for creating such a similar
 project—is Boost. Boost is an enormously large and complex suite of utility
 project—is Boost. Boost is an enormously large and complex suite of utility
 libraries that works with almost every C++ compiler in existence. This
 libraries that works with almost every C++ compiler in existence. This
 compatibility has its cost: arcane template tricks and workarounds are
 compatibility has its cost: arcane template tricks and workarounds are