Print out how ./configure was called

This will make debugging and tracing back from logs much easier

configure.ac

@@ -9584,6 +9584,8 @@ echo "   * keylog export:              $ENABLED_KEYLOG_EXPORT"
 echo ""
 echo "---"
 
+echo "./configure flags: $(./config.status --config)"
+
 fi # $silent != yes
 
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