databases/py-dbf: Fix build with setuptools 58.0.0+

With hat:	python

databases/py-dbf/Makefile

@@ -11,7 +11,7 @@ COMMENT=	Pure python package for reading/writing dbf files
 
 LICENSE=	BSD3CLAUSE
 
-USES=		python:3.6+
+USES=		dos2unix python:3.6+
 USE_PYTHON=	autoplist distutils
 NO_ARCH=	yes
 

databases/py-dbf/files/patch-2to3

@@ -0,0 +1,13 @@
+--- dbf/_index.py.orig	2022-03-15 19:06:56 UTC
++++ dbf/_index.py
+@@ -9,8 +9,8 @@ class IndexFile(object):
+         filename += '.pdx'
+         if not os.path.exists(filename):
+             self.index_file = open(filename, 'r+b')
+-            self.index_file.write('\xea\xaf\x37\xbf'    # signature
+-                '\x00'*8                                # two non-existant lists
++            self.index_file.write('\xea\xaf\x37\xbf',   # signature
++                '\x00'*8,                               # two non-existant lists
+                 '\x00'*500)                             # and no indices
+             return
+         index_file = self.index_file = open(filename, 'r+b')