The versionstring tests hit the network so should only run when
network tests are enabled.
Also remove the print statement which confuses the test output and
add it to the test failure message instead.
(Bitbake rev: 6c046660cfc4fb3792a42aeafff91a13f68a2e89)
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>