Add test for record compression in ssl-opt.sh

Deprecated but still needs to be tested.
diff --git a/tests/ssl-opt.sh b/tests/ssl-opt.sh
index afaae69..3d0ca87 100755
--- a/tests/ssl-opt.sh
+++ b/tests/ssl-opt.sh
@@ -996,6 +996,18 @@
             -s "Protocol is DTLSv1.2" \
             -s "Ciphersuite is TLS-ECDHE-RSA-WITH-CHACHA20-POLY1305-SHA256"
 
+requires_config_enabled MBEDTLS_ZLIB_SUPPORT
+run_test    "Default (compression enabled)" \
+            "$P_SRV debug_level=3" \
+            "$P_CLI debug_level=3" \
+            0 \
+            -s "Allocating compression buffer" \
+            -c "Allocating compression buffer" \
+            -s "Record expansion is unknown (compression)" \
+            -c "Record expansion is unknown (compression)" \
+            -S "error" \
+            -C "error"
+
 requires_config_enabled MBEDTLS_X509_TRUSTED_CERTIFICATE_CALLBACK
 run_test    "CA callback on client" \
             "$P_SRV debug_level=3" \