Getting domain name

src/freedombone-utils-android

                   echo "      \"clients\": ["; } >> "$plinth_api"
 
                 read_config_param "${app_name_upper}_DOMAIN_NAME"
-                domain_name=$(("${app_name_upper}_DOMAIN_NAME"))
+                test_domain_name="${app_name_upper}_DOMAIN_NAME"
+                domain_name=${!test_domain_name}
                 if [[ "$domain_name" != "0" && "$app_name" != 'matrix' ]]; then
                     { echo '        {';
                       echo "          \"name\": \"${app_name}\",";