In 1.1, the Groovy template support did not check that its configured
template location exists. A check was added in 1.2, however this
breaks CLI web applications that don't have the expected templates
location.

Rather than reintroducing 1.1's behaviour by removing the check, this
commit updates the CLI to set
spring.groovy.template.check-template-location to false by default.
This allows flow-blown applications to benefit from the check, while
allowing CLI apps to behave as they did in 1.1.

Closes gh-1959