External gadgets on JIRA 6.1.3 do not work

External gadgets do not work on JIRA 6.1.3 when Trusted Applications is configured between two applications. However, oAuth authentication seems to be working fine.

This issue can occur in a variety of gadgets (i.e. Overdue Review gadget, Confluence Page gadget) among different products, follow is the description of how to replicate this issue with JIRA and Confluence.

Steps to reproduce

1. Setup JIRA 6.1.3 and Confluence 5.3.4
2. Configure 'Trusted Application' application link between the two applications
3. Add "Show Confluence Page" gadget on JIRA
4. You will face error on the gadget as example in gadget.jpg with HTTP Status 401 Unauthorized Error.

If DEBUG is enabled on Confluence, the following will be thrown

2013-12-10 18:11:10,724 DEBUG [http-8090-17] [auth.trustedapps.filter.TrustedApplicationFilterAuthenticator] setFailureHeader BAD_PROTOCOL_VERSION;	Unsupported protocol version: {0}. required {1};	["0","2"]
java.lang.RuntimeException: BAD_PROTOCOL_VERSION;	Unsupported protocol version: {0}. required {1};	["0","2"]
	at com.atlassian.security.auth.trustedapps.filter.TrustedApplicationFilterAuthenticator.setFailureHeader(TrustedApplicationFilterAuthenticator.java:247)
	at com.atlassian.security.auth.trustedapps.filter.TrustedApplicationFilterAuthenticator.authenticate(TrustedApplicationFilterAuthenticator.java:73)