Enhancements

Refine libcurl logs.
Do not retry web request on API mode.
Optimize codes.

src/utils/logger.cpp

@@ -26,7 +26,8 @@ std::string getTime(int type)
         format = "%Y%m%d-%H%M%S";
         break;
     case 2:
-        format = "%Y/%m/%d %a %H:%M:%S." + std::string(cMillis);
+        format = "%Y/%m/%d %a %H:%M:%S.";
+        format += cMillis;
         break;
     case 3:
     default: