[misc] fix a potential memory leak bug and update README files.

Author: winshining

README.CN.md

@@ -168,12 +168,12 @@ nginx-http-flv-module包含了[nginx-rtmp-module](https://github.com/arut/nginx-
 
 配置项`rtmp_auto_push`，`rtmp_auto_push_reconnect`和`rtmp_socket_dir`在Windows上不起作用，除了Windows 10 17063以及后续版本之外，因为多进程模式的`relay`需要Unix domain socket的支持，详情请参考[Unix domain socket on Windows 10](https://blogs.msdn.microsoft.com/commandline/2017/12/19/af_unix-comes-to-windows)。
 
-最好将配置项`worker_processes`设置为1，因为`ngx_rtmp_stat_module`在多进程模式下每次只能获取一个进程的统计数据。如果统计数据不重要，那么可以将它设置为大于1的数字，最好与CPU的核心数保持一致。
+最好将配置项`worker_processes`设置为1，因为`ngx_rtmp_stat_module`和`ngx_rtmp_control_module`在多进程模式下有问题，另外，`vhost`功能在多进程模式下还有问题。
 
-    worker_processes  4; #运行在Windows上时，设置为1，因为Windows不支持Unix domain socket
+    worker_processes  1; #运行在Windows上时，设置为1，因为Windows不支持Unix domain socket
     #worker_processes  auto; #1.3.8和1.2.5以及之后的版本
 
-    worker_cpu_affinity  0001 0010 0100 1000; #只能用于FreeBSD和Linux
+    #worker_cpu_affinity  0001 0010 0100 1000; #只能用于FreeBSD和Linux
     #worker_cpu_affinity  auto; #1.9.10以及之后的版本
 
     error_log logs/error.log error;
@@ -306,3 +306,6 @@ nginx-http-flv-module包含了[nginx-rtmp-module](https://github.com/arut/nginx-
         }
     }
 
+# Red Har Enterprise Linux 6（CentOS 6）和7（CentOS 7）上的rpm安装包已可用
+
+详情见[nginx-http-flv-module-package](https://github.com/winshining/nginx-http-flv-module-package)。

README.md

@@ -168,12 +168,12 @@ Since some players don't support HTTP chunked transmission, it's better to speci
 
 The directives `rtmp_auto_push`, `rtmp_auto_push_reconnect` and `rtmp_socket_dir` will not function on Windows except on Windows 10 17063 and later versions, because `relay` in multiple processes mode needs help of Unix domain socket, please refer to [Unix domain socket on Windows 10](https://blogs.msdn.microsoft.com/commandline/2017/12/19/af_unix-comes-to-windows) for details.
 
-The directive `worker_processes` of value 1 is preferable to other values, because `ngx_rtmp_stat_module` can only get the statistics of one process at a time in multi-processes mode. If the statistics is unimportant, it can be set as number greater than 1, it is better to set it as the number of CPU cores.
+The directive `worker_processes` of value 1 is preferable to other values, because there are something wrong with `ngx_rtmp_stat_module` and `ngx_rtmp_control_module` in multi-processes mode, in addtion, `vhost` feature is not perfect in multi-processes mode yet.
 
-    worker_processes  4; #should be 1 for Windows, for it doesn't support Unix domain socket
+    worker_processes  1; #should be 1 for Windows, for it doesn't support Unix domain socket
     #worker_processes  auto; #from versions 1.3.8 and 1.2.5
 
-    worker_cpu_affinity  0001 0010 0100 1000; #only available on FreeBSD and Linux
+    #worker_cpu_affinity  0001 0010 0100 1000; #only available on FreeBSD and Linux
     #worker_cpu_affinity  auto; #from version 1.9.10
 
     error_log logs/error.log error;
@@ -307,3 +307,6 @@ The directive `worker_processes` of value 1 is preferable to other values, becau
         }
     }
 
+# rpm packages on Red Hat Enterprise Linux 6 (CentOS 6) and 7 (CentOS 7) are available
+
+Please refer to [nginx-http-flv-module-package](https://github.com/winshining/nginx-http-flv-module-package).

ngx_rtmp_relay_module.c

@@ -470,7 +470,7 @@ ngx_rtmp_relay_create_connection(ngx_rtmp_conf_ctx_t *cctx, ngx_str_t* name,
     if (addr->sockaddr->sa_family == AF_UNIX) {
         client = ngx_pcalloc(pool, rctx->url.len + 8);
         if (client == NULL) {
-            return NULL;
+            goto clear;
         }
 
         *ngx_cpymem(client, rctx->url.data,