Avoid rewriting the shebang.

The ebuild will take care of this when replicating the script for each of the
supported python implementations.

--- a/python-tools-setup.py
+++ b/python-tools-setup.py
@@ -43,7 +43,7 @@
             f = prefix + s
             # If we have a defined python version, use it instead of the system
             # default
-            if 'PYTHON' in os.environ:
+            if False:
                 lines = open(os.path.basename(s)).readlines()
                 lines[0] = '#! /usr/bin/env %s\n' % os.environ['PYTHON']
                 open(f, 'w').write("".join(lines))