Configure: Reword the summary output

In commit 820e414d

 (pr #5247) the summary output of the
Configure command was optimized towards instructing people
how to create issue reports.

It turned out that the wording of this message can confuse new
OpenSSL users and make them think that they are seeing an error
message. This commit makes the summary output start with a success
to prevent a misunderstanding. Also it gives more hints to new
OpenSSL users.

Reviewed-by: Richard Levitte <levitte@openssl.org>
Reviewed-by: Matt Caswell <matt@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/7499)