[mod_openssl] issue error trace if < openssl 1.1.1

src/mod_openssl.c

@@ -2916,6 +2916,14 @@ SETDEFAULTS_FUNC(mod_openssl_set_defaults)
             mod_openssl_merge_config(&p->defaults, cpv);
     }
 
+  #if OPENSSL_VERSION_NUMBER < 0x10101000L \
+   && !defined(LIBRESSL_VERSION_NUMBER)
+    log_error(srv->errh, __FILE__, __LINE__, "SSL:"
+      "openssl library version is outdated and has reached end-of-life.  "
+      "As of 1 Jan 2020, only openssl 1.1.1 and later continue to receive "
+      "security patches from openssl.org");
+  #endif
+
     return mod_openssl_set_defaults_sockets(srv, p);
 }