feat: add only section not has filed name; for examlpe:[section1] dat…

[wangwenqiangGitHub]

…a1 \n data2 \n data3\n

[wangwenqiangGitHub]

 [section1]
data1
data2
data3

 ini::IniFile testIni;
 testIni.setVectorFieldsFlag(true);
testIni.load("test.ini");
std::string vec = sysgo["section1"]["section1"].as<std::string>();