Update test to correct name of metric for request that returns a 401

The request is being made to '/' and, while the application does have
a mapping for '/', that mapping is not looked for before Spring
Security's filter rejects the request with a 401. This means that the
request is considered to be unmapped and this is reflected in the
metric's name.

See #1331 and #1333
Merge branch '1.1.x'