Don't die if writing to html2lrf-verbose fails.

src/calibre/ebooks/lrf/html/convert_from.py

@@ -336,10 +336,13 @@ class HTMLConverter(object):
             tdir = tempfile.gettempdir()
             if not os.path.exists(tdir):
                 os.makedirs(tdir)
+            try:
                 dump = open(os.path.join(tdir, 'html2lrf-verbose.html'), 'wb')
                 dump.write(unicode(soup).encode('utf-8'))
                 self.logger.info(_('Written preprocessed HTML to ')+dump.name)
                 dump.close()
+            except:
+                pass
             
         return soup