Crowd client <=2.3.4 produces SSO tokens that are incompatible with >=2.3.5 on IPv6 addresses with scopes

The crowd HTTP authentication library (i.e. the one using REST) sends an IP address when requesting an SSO token. An IPv6 address may have a zone id in the address (e.g. fe80::1%lo0, fe80::21f:5bff:fe33:57c4%en0 on Mac). In fixing CWD-2711 in 2.3.5 and later we remove the zone id before requesting the SSO token. As the address is used in the generation of the token, it means that a SSO token generated from <=2.3.4 is incompatible with one produced from >=2.3.5 when using IPv6 addresses with zone ids.

Example:

JIRA has Crowd 2.3.6.
Confluence has Crowd 2.3.2.

1. User logs into JIRA.
2. JIRA sends login request to Crowd server with IP address ::1.
3. JIRA logs user in and returns SSO token from Crowd in Cookie.

1. User logs into Confluence on same box.
2. Confluence sends SSO token to Crowd server with IP address ::1%0.
3. Crowd rejects the SSO token because the IP addresses do not match.
4. Confluence tells the user of the failure.