Refine the random id by srs_random_str

trunk/src/app/srs_app_latest_version.cpp

@@ -54,12 +54,7 @@ srs_error_t SrsLatestVersion::start()
         return srs_success;
     }
 
-    char buf[10];
-    srs_random_generate(buf, sizeof(buf));
-    for (int i = 0; i < (int)sizeof(buf); i++) {
-        buf[i] = 'a' + uint8_t(buf[i])%25;
-    }
-    server_id_ = string(buf, sizeof(buf));
+    server_id_ = srs_random_str(10);
 
     return trd_->start();
 }