[misc] add build status, update README files and fix a compilation error.

Author: winshining

.travis.yml

@@ -0,0 +1,11 @@
+language: c
+
+install:
+  - cd ..
+  - wget http://nginx.org/download/nginx-1.12.2.tar.gz
+  - tar zxvf nginx-1.12.2.tar.gz
+  - cd nginx-1.12.2
+
+script:
+  - ./configure --add-module=../nginx-http-flv-module && make
+  - ./configure --add-dynamic-module=../nginx-http-flv-module && make

README.CN.md

@@ -1,5 +1,7 @@
 # nginx-http-flv-module
 
+[![Build Status](https://travis-ci.org/winshining/nginx-http-flv-module.svg?branch=master)](https://travis-ci.org/winshining/nginx-http-flv-module)
+
 基于[nginx-rtmp-module](https://github.com/arut/nginx-rtmp-module)的流媒体服务器。
 
 # 功能

README.md

@@ -1,5 +1,7 @@
 # nginx-http-flv-module
 
+[![Build Status](https://travis-ci.org/winshining/nginx-http-flv-module.svg?branch=master)](https://travis-ci.org/winshining/nginx-http-flv-module)
+
 Media streaming server based on [nginx-rtmp-module](https://github.com/arut/nginx-rtmp-module).
 
 # Features

ngx_rtmp_live_module.c

@@ -1187,10 +1187,11 @@ ngx_rtmp_live_data(ngx_rtmp_session_t *s, ngx_rtmp_header_t *h,
     ngx_uint_t                      peers;
     uint32_t                        delta;
     ngx_rtmp_live_chunk_stream_t   *cs;
-
+#ifdef NGX_DEBUG
     u_char                         *msg_type;
 
     msg_type = (u_char *)out_elts[0].data;
+#endif
 
     lacf = ngx_rtmp_get_module_app_conf(s, ngx_rtmp_live_module);
     if (lacf == NULL) {