Remove bad import

My bad for not catching this before pushing.

src/python/pants/backend/python/tasks/python_binary_create.py

@@ -15,7 +15,6 @@
                                                             has_python_sources, has_resources,
                                                             is_python_target)
 from pants.backend.python.subsystems.python_native_code import PythonNativeCode
-from pants.backend.python.subsystems.python_setup import PythonSetup
 from pants.backend.python.targets.python_binary import PythonBinary
 from pants.backend.python.targets.python_requirement_library import PythonRequirementLibrary
 from pants.base.build_environment import get_buildroot
@@ -141,7 +140,7 @@ def _create_binary(self, binary_tgt, results_dir):
         if is_python_target(tgt):
           constraint_tgts.append(tgt)
 
-      # Add global and target-level interpreter compatibility constraints to pex info.
+      # Add target-level and possibly global interpreter compatibility constraints to pex info.
       pex_builder.add_interpreter_constraints_from(constraint_tgts)
 
       # Dump everything into the builder's chroot.