Process events with processEventsWhileBlocked() when blocked.

When we are blocked and a few events a processed from time to time, it
is smarter to call the event handler a few times in order to handle the
accept, read, write, close cycle of a client in a single pass, otherwise
there is too much latency added for clients to receive a reply while the
server is busy in some way (for example during the DB loading).

src/aof.c

@@ -560,7 +560,7 @@ int loadAppendOnlyFile(char *filename) {
         /* Serve the clients from time to time */
         if (!(loops++ % 1000)) {
             loadingProgress(ftello(fp));
-            aeProcessEvents(server.el, AE_FILE_EVENTS|AE_DONT_WAIT);
+            processEventsWhileBlocked();
         }
 
         if (fgets(buf,sizeof(buf),fp) == NULL) {