Make sending downloads using legacy protocol work with sv_dlRate 1000

Send snapshot with each download block so that client updates reliable
acknowledge, otherwise client can error when asking for next block via
nextdl reliable command.

code/server/server.h

@@ -397,6 +397,9 @@ void SV_WriteFrameToClient (client_t *client, msg_t *msg);
 void SV_SendMessageToClient( msg_t *msg, client_t *client );
 void SV_SendClientMessages( void );
 void SV_SendClientSnapshot( client_t *client );
+#ifdef ELITEFORCE
+void SV_WriteSnapshotToClient( client_t *client, msg_t *msg );
+#endif
 
 //
 // sv_game.c

code/server/sv_client.c

@@ -1259,9 +1259,14 @@ int SV_SendDownloadMessages(void)
 			if(retval)
 			{
 #ifdef ELITEFORCE
-				if(!msg.compat)
+				if(msg.compat)
+				{
+					// compat clients need svc_snapshot to update reliableAcknowledge
+					SV_WriteSnapshotToClient(cl, &msg);
+				}
+				else
 #endif
-				MSG_WriteByte(&msg, svc_EOF);
+					MSG_WriteByte(&msg, svc_EOF);
 				SV_Netchan_Transmit(cl, &msg);
 				numDLs += retval;
 			}

code/server/sv_snapshot.c

@@ -119,7 +119,10 @@ static void SV_EmitPacketEntities( clientSnapshot_t *from, clientSnapshot_t *to,
 SV_WriteSnapshotToClient
 ==================
 */
-static void SV_WriteSnapshotToClient( client_t *client, msg_t *msg ) {
+#ifndef ELITEFORCE
+static
+#endif
+void SV_WriteSnapshotToClient( client_t *client, msg_t *msg ) {
 	clientSnapshot_t	*frame, *oldframe;
 	int					lastframe;
 	int					i;
@@ -671,12 +674,7 @@ void SV_SendClientMessages(void)
 		if(!c->state)
 			continue;		// not connected
 
-#ifdef ELITEFORCE
-		// compat clients need svc_snapshot to update reliableAcknowledge
-		if(*c->downloadName && !c->compat)
-#else
 		if(*c->downloadName)
-#endif
 			continue;		// Client is downloading, don't send snapshots
 
 		if(c->netchan.unsentFragments || c->netchan_start_queue)