Use app router in OnTimeoutPacket handler

[chatton]

Description

We missed updating the message server in the timeout packet implementation, (all the tests correctly queried the legacy stack which is why they passed)

closes: #XXXX

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[damiannolan]

nice catch!

[sonarcloud]

Quality Gate passed for 'ibc-go'

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarCloud