bug in Participant comparison

[Changaco]

Description: the comparison participant != None returns False instead of True.

Origin of the bug: gratipay/gratipay.com@a25a4bb#diff-278aa1963da2c7006b0639e16b0130d9R47

Severity: low, I haven't been able to find any exploitable code.

Fix:

--- a/gratipay/models/participant.py
+++ b/gratipay/models/participant.py
@@ -78,7 +78,7 @@ class Participant(Model, MixinTeam):

     def __ne__(self, other):
         if not isinstance(other, Participant):
-            return False
+            return True
         return self.username != other.username

     def __repr__(self):

[Changaco]

@whit537 I have a branch ready for this, should I open a PR ?

[chadwhitacre]

@Changaco I think we should figure out how to fix security bugs on a fork in this private repo. It's not a big deal here but better to learn the process here than on a higher-risk bug. cf. gratipay/security-00003#1 (comment)