Limit number ffdh test cases (ffdhe2048, ffdhe8192)

Signed-off-by: Przemek Stekiel <przemyslaw.stekiel@mobica.com>
diff --git a/tests/ssl-opt.sh b/tests/ssl-opt.sh
index 155ed6a..0043659 100755
--- a/tests/ssl-opt.sh
+++ b/tests/ssl-opt.sh
@@ -695,7 +695,7 @@
         OPENSSL_3_X_AVAILABLE="NO"
     fi
     if [ -z "${OPENSSL_3_X_AVAILABLE:-}" ]; then
-        if which $OPENSSL_NEXT 2>&1 | grep openssl-3 >/dev/null
+        if $OPENSSL_NEXT version 2>&1 | grep "OpenSSL 3." >/dev/null
         then
             OPENSSL_3_X_AVAILABLE="YES"
         else