move import into ifmain block

setupbase.py

@@ -336,8 +336,8 @@ def find_entry_points():
 
 script_src = """#!{executable}
 # This script was automatically generated by setup.py
-from {mod} import {func}
 if __name__ == '__main__':
+    from {mod} import {func}
     {func}()
 """