Update scripts/openssl_srtp.test

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

Author: kaleb-himes

scripts/openssl_srtp.test

@@ -54,7 +54,7 @@ generate_port() {
 
         [ $collision -eq 0 ] && break
 
-        ((attempts++))
+        attempts=$((attempts + 1))
         if [ $attempts -ge 100 ]; then
             echo "ERROR: generate_port could not find a free port after 100 attempts"
             exit 1