Revert "bpo-37785: Fix xgettext warning in argparse (GH-15161)" (GH-16082)

This reverts commit b50eff6590 because
it's an incompatible change that would have broken the existing
translations.

Lib/argparse.py

@@ -1207,9 +1207,8 @@ class FileType(object):
             return open(string, self._mode, self._bufsize, self._encoding,
                         self._errors)
         except OSError as e:
-            args = {'filename': string, 'error': e}
-            message = _("can't open '%(filename)s': %(error)s")
-            raise ArgumentTypeError(message % args)
+            message = _("can't open '%s': %s")
+            raise ArgumentTypeError(message % (string, e))
 
     def __repr__(self):
         args = self._mode, self._bufsize

Misc/NEWS.d/next/Library/2019-08-07-14-49-22.bpo-37785.y7OlT8.rst

@@ -1 +0,0 @@
-Fix xgettext warnings in :mod:`argparse`.