Configure: Reword the summary output

In commit 820e414d2830 (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)

Configure

@@ -2799,10 +2799,16 @@ print <<"EOF";
 
 **********************************************************************
 ***                                                                ***
-***   If you want to report a building issue, please include the   ***
-***   output from this command:                                    ***
+***   OpenSSL has been successfully configured                     ***
 ***                                                                ***
-***     perl configdata.pm --dump                                  ***
+***   If you encounter a problem while building, please open an    ***
+***   issue on GitHub <https://github.com/openssl/openssl/issues>  ***
+***   and include the output from the following command:           ***
+***                                                                ***
+***       perl configdata.pm --dump                                ***
+***                                                                ***
+***   (If you are new to OpenSSL, you might want to consult the    ***
+***   'Troubleshooting' section in the INSTALL file first)         ***
 ***                                                                ***
 **********************************************************************
 EOF