Add GCM dependency to "Per-version suites: TLS 1.2"

Test was failing with error:
unknown ciphersuite: 'TLS-RSA-WITH-AES-128-GCM-SHA256'

Signed-off-by: Przemek Stekiel <przemyslaw.stekiel@mobica.com>
diff --git a/tests/ssl-opt.sh b/tests/ssl-opt.sh
index 75ba4b7..fbf3bf7 100755
--- a/tests/ssl-opt.sh
+++ b/tests/ssl-opt.sh
@@ -6595,6 +6595,7 @@
 
 requires_config_enabled MBEDTLS_CAMELLIA_C
 requires_config_enabled MBEDTLS_AES_C
+requires_config_enabled MBEDTLS_GCM_C
 run_test    "Per-version suites: TLS 1.2" \
             "$P_SRV version_suites=TLS-RSA-WITH-CAMELLIA-128-CBC-SHA,TLS-RSA-WITH-AES-256-CBC-SHA,TLS-RSA-WITH-AES-128-CBC-SHA,TLS-RSA-WITH-AES-128-GCM-SHA256" \
             "$P_CLI force_version=tls12" \