6590: gramps40 asciidoc.py crashes for at least some reports

svn: r21873

gramps/plugins/docgen/asciidoc.py

@@ -30,6 +30,7 @@
 # python modules
 #
 #------------------------------------------------------------------------
+from __future__ import unicode_literals
 import io
 import sys
 #------------------------------------------------------------------------
@@ -158,7 +159,6 @@ class AsciiDoc(BaseDoc,TextDoc):
 
         try:
             self.f = io.open(self.filename,"w",
-                             encoding='ascii',
                              errors = 'backslashreplace')
         except Exception as msg:
             errmsg = "%s\n%s" % (_("Could not create %s") % self.filename, msg)