bpo-33711: Fix license generation error in msi.py

[native-api]

c:\Users\Sasha\Documents\cpython\Tools\msi>python msi.py
Traceback (most recent call last):
  File "msi.py", line 1372, in <module>
    add_files(db)
  File "msi.py", line 956, in add_files
    generate_license()
  File "msi.py", line 928, in generate_license
    raise ValueError, "Could not find "+srcdir+"/externals/"+pat
ValueError: Could not find c:\Users\Sasha\Documents\cpython/externals/db-*

The dir in externals is actually called bsddb-<version>.
Bug caused by 986b7ff .
Doesn't affect 3.x 'cuz the bsddb module has been dropped.

https://bugs.python.org/issue33711

[akruis]

Had the same problem. The patch works for me.