have a nicer UNKNOWN intro paragraph [rt.cpan.org #39710]

[xdg]

https://rt.cpan.org/Ticket/Display.html?id=39710

Suggestion from sisyphus:

I guess my only quibble would be that the diagnostic still implies that the
author has made a mistake. I'm looking at the paragraph:

--------------------------------------------
This could be because your distribution had an error during the make/build
stage, did not define tests, tests could not be found, because your
tests were
interrupted before they finished, or because the results of the tests
could not
be parsed.  You may wish to consult the CPAN Testers Wiki:
--------------------------------------------

The super-sensitive module author will still read that as implying that
"there's something wrong with your distro", even though the real problem
could be that the tester's environment is lacking something (eg the mpc
library).

Maybe something like:

--------------------------------------------
This could be because the tester's build environment lacked a necessary
element, because your distribution had an error during the make/build
stage, because tests were not defined or could not be found, because
your tests were interrupted before they finished, or because the results
of the tests could not be parsed.  You may wish to consult the CPAN
Testers Wiki:
--------------------------------------------