Added fix for Attribute error when ROTATE_REFRESH_TOKENS=True and blacklist app is not installed.

[rohitrhmn1]

When the blacklist app is not installed, the Refresh Token endpoint fails with Attribute error.

Moving the outstand method inside the if block fixes the issue.

[MarcoGlauser]

Related to this issue with the 5.5.0 release
#875

[vgrozdanic]

Token needs to be added to OutstandingTable after the JTI claim is re-set, otherwise it will end up with the old claim in the table.

TBH i am not sure what is the best approach here, probably some small refactor can make this better, or worst case scenario another try-catch and checking of the BLACKLIST_AFTER_ROTATION setting needs to be done

[rohitrhmn1]

Probably adding a check inside outstand method can help fix the issue.

[rohitrhmn1]

Also, the blacklist function already has the method to Outstand the revoked token:

def blacklist(self) -> BlacklistedToken:
            """
            Ensures this token is included in the outstanding token list and
            adds it to the blacklist.
            """
            jti = self.payload[api_settings.JTI_CLAIM]
            exp = self.payload["exp"]
            user_id = self.payload.get(api_settings.USER_ID_CLAIM)
            User = get_user_model()
            try:
                user = User.objects.get(**{api_settings.USER_ID_FIELD: user_id})
            except User.DoesNotExist:
                user = None
            
            # Ensure outstanding token exists with given jti
            token, _ = OutstandingToken.objects.get_or_create(
                jti=jti,
                defaults={
                    "user": user,
                    "created_at": self.current_time,
                    "token": str(self),
                    "expires_at": datetime_from_epoch(exp),
                },
            )

            return BlacklistedToken.objects.get_or_create(token=token)

Comparing it with Outstand method:

def outstand(self) -> OutstandingToken:
         """
         Ensures this token is included in the outstanding token list and
         adds it to the outstanding token list if not.
         """
         jti = self.payload[api_settings.JTI_CLAIM]
         exp = self.payload["exp"]
         user_id = self.payload.get(api_settings.USER_ID_CLAIM)
         User = get_user_model()
         try:
             user = User.objects.get(**{api_settings.USER_ID_FIELD: user_id})
         except User.DoesNotExist:
             user = None
 
         # Ensure outstanding token exists with given jti
         return OutstandingToken.objects.get_or_create(
             jti=jti,
             defaults={
                 "user": user,
                 "created_at": self.current_time,
                 "token": str(self),
                 "expires_at": datetime_from_epoch(exp),
             },
         )

Both the functions have the similar functionality. Better suggestion would be to keep the OutstandingToken query in the outstand method and remove it from blacklist method.