Fix #744 http callback set a wrong default port (#777)

* Add port verify

Code is more robust

* Verify port

Verify port

* Change hard code to defined.

Change hard code to defined.

trunk/src/protocol/srs_http_stack.cpp

@@ -3037,7 +3037,7 @@ int SrsHttpUri::initialize(string _url)
 {
     int ret = ERROR_SUCCESS;
     
-    port = 0;
+    //port = 0;
     schema = host = path = query = "";
     
     url = _url;
@@ -3063,6 +3063,9 @@ int SrsHttpUri::initialize(string _url)
     if(!field.empty()){
         port = atoi(field.c_str());
     }
+	if(port<=0){
+		port = SRS_DEFAULT_HTTP_PORT;
+	}
     
     path = get_uri_field(url, &hp_u, UF_PATH);
     srs_info("parse url %s success", purl);