Replace all include guards by #pragma once

It’s $CURRENT_YEAR

louloulibs/utils/string.hpp

@@ -1,5 +1,5 @@
-#ifndef STRING_UTILS_HPP_INCLUDED
-#define STRING_UTILS_HPP_INCLUDED
+#pragma once
+
 
 #include <vector>
 #include <string>
@@ -7,4 +7,4 @@
 bool to_bool(const std::string& val);
 std::vector<std::string> cut(const std::string& val, const std::size_t size);
 
-#endif /* STRING_UTILS_HPP_INCLUDED */
+