Fix: admin RPC webhook queue limit removal and timeout reduction (#5163)

When using subscribe at admin RPC port to send webhooks for the transaction stream to a backend, on large(r) ledgers the endpoint receives fewer HTTP POSTs with TX information than the amount of transactions in a ledger. This change removes the hardcoded queue length to avoid dropping TX notifications for the admin-only command. In addition, the per-request TTL for outgoing RPC HTTP calls has been reduced from 10 minutes to 30 seconds.

src/xrpld/net/detail/RPCCall.cpp

@@ -1884,9 +1884,7 @@ fromNetwork(
     constexpr auto RPC_REPLY_MAX_BYTES = megabytes(256);
 
     using namespace std::chrono_literals;
-    // auto constexpr RPC_NOTIFY = 10min; // Wietse: lolwut 10 minutes for one
-    // HTTP call?
-    auto constexpr RPC_NOTIFY = 30s;
+    auto constexpr RPC_WEBHOOK_TIMEOUT = 30s;
 
     HTTPClient::request(
         bSSL,
@@ -1903,7 +1901,7 @@ fromNetwork(
             std::placeholders::_2,
             j),
         RPC_REPLY_MAX_BYTES,
-        RPC_NOTIFY,
+        RPC_WEBHOOK_TIMEOUT,
         std::bind(
             &RPCCallImp::onResponse,
             callbackFuncP,

src/xrpld/net/detail/RPCSub.cpp

@@ -80,15 +80,6 @@ public:
     {
         std::lock_guard sl(mLock);
 
-        // Wietse: we're not going to limit this, this is admin-port only, scale
-        // accordingly Dropping events just like this results in inconsistent
-        // data on the receiving end if (mDeque.size() >= eventQueueMax)
-        // {
-        //     // Drop the previous event.
-        //     JLOG(j_.warn()) << "RPCCall::fromNetwork drop";
-        //     mDeque.pop_back();
-        // }
-
         auto jm = broadcast ? j_.debug() : j_.info();
         JLOG(jm) << "RPCCall::fromNetwork push: " << jvObj;
 
@@ -186,9 +177,6 @@ private:
     }
 
 private:
-    // Wietse: we're not going to limit this, this is admin-port only, scale
-    // accordingly enum { eventQueueMax = 32 };
-
     boost::asio::io_service& m_io_service;
     JobQueue& m_jobQueue;