Fix a typo in the test HTTP server

The test HTTP server code we use for testing had a typo where the the cookie
inserted was "JESSIONID" instead of "JSESSIONID". This led to confusion
and failing tempest tests. This patch changes it to "JSESSIONID" to avoid
confusion.

Change-Id: I7d6387c71ed96edead3a6a2338b0c78250d4c50d
3 files changed