Convert exception to unicode instead of str.

The result of the conversion is used as a message, hence needs to be
unicode string.

views.py

@@ -68,7 +68,7 @@ class ForgottenPasswordSendMailController(controller.Controller):
         except ValidationError:
             raise
         except Exception, exc:
-            msg = str(exc)
+            msg = unicode(exc)
         else:
             msg = self._cw._(u'An email has been sent, follow instructions in there to change your password.')
         raise Redirect(self._cw.build_url('pwdsent', __message=msg))