tests: improve test-patchbomb-tls.t by by logging errors and data The actual SSL error might be like: ::1 ssl error: [SSL: TLSV1_ALERT_UNKNOWN_CA] tlsv1 alert unknown ca (_ssl.c:1002) and will probably vary so much that it can't be checked in the test. It is however very useful when debugging failures.

tests: show test-patchbomb-tls.t smtp server log Improve test coverage by exposing what the smtp server actually receives. Make dummystmtpd redirect stderr to a log file.