Update to build 20; fixed client->server messages

Fixed bug with reading messages when messagereader::getremaining() is called.
Fixed kicking clients when a client->server message with no data (beside subchannel/variant) was sent; server was mistakenly set to not accept empty messages, and due to it seeing a message corruption, it kicked the client immediately.
Fixed crash caused by lock being freed twice during some message parsing errors.
Also switched kicks for broken messages from clean exit to immediate exit. It may not be safe to wait for connection to finish processing, as client could be pouring messages into their end.

Author: SortaCore

Lacewing/Lacewing.h

@@ -1847,7 +1847,7 @@ namespace lacewing {
 struct relayserverinternal;
 struct relayserver
 {
-	static const int buildnum = 19;
+	static const int buildnum = 20;
 
 	void * internaltag, * tag = nullptr;
 

Lacewing/MessageReader.h

@@ -115,7 +115,7 @@ class messagereader
 			return this->buffer;
 
 		std::string_view remaining(this->buffer + offset, bytesleft());
-		offset += size;
+		offset += remaining.size();
 
 		if (!allowempty && (remaining.empty() || !remaining.front()))
 			failed = true;

Lacewing/RelayServer.cc

@@ -1715,7 +1715,7 @@ bool relayserverinternal::client_messagehandler(std::shared_ptr<relayserver::cli
 			cliReadLock.lw_unlock();
 
 			const lw_ui8 subchannel = reader.get <lw_ui8> ();
-			std::string_view message3 = reader.getremaining(false);
+			std::string_view message3 = reader.getremaining();
 
 			if (reader.failed)
 			{
@@ -1948,14 +1948,15 @@ bool relayserverinternal::client_messagehandler(std::shared_ptr<relayserver::cli
 
 		if (!trustedClient)
 		{
-			// LW_ESCALATION_NOTE
-			// auto cliWriteLock = cliReadLock.lw_upgrade();
 			client->_readonly = true;
 
-			cliReadLock.lw_unlock();
+			// LW_ESCALATION_NOTE
+			// auto cliWriteLock = cliReadLock.lw_upgrade();
+			if (cliReadLock.isEnabled())
+				cliReadLock.lw_unlock();
 			auto cliWriteLock = client->lock.createWriteLock();
 
-			client->socket->close(); // TODO: Should be immediate?
+			client->socket->close(true); // immediate disconnect
 		}
 
 		// only return false if socket is emergency closing and