show no of txpool if not zero only

src/page.h

@@ -833,6 +833,7 @@ namespace xmreg
                     {"alt_blocks_no"     , current_network_info.alt_blocks_no},
                     {"tx_pool_size"      , current_network_info.tx_pool_size},
                     {"is_current_info"   , is_network_info_current},
+                    {"is_pool_size_zero" , (current_network_info.tx_pool_size == 0)},
                     {"age"               , network_info_age.first},
                     {"age_format"        , network_info_age.second},
             };

src/templates/mempool_error.html

@@ -6,9 +6,9 @@
     
    <p>Mempool data preparation for the front page failed.
     Its processing
-       {{#network_info}}{{#tx_pool_size}}({{tx_pool_size}} txs){{/tx_pool_size}}{{/network_info}}
+       {{#network_info}}{{^is_pool_size_zero}}({{tx_pool_size}} txs){{/is_pool_size_zero}}{{/network_info}}
        took longer than expected and it timed out.
-    To view mempool without time constrain,
+    To view the mempool without time constrain,
     go to dedicated mempool page: <a href="/mempool">memory pool</a>
     </p>