Adjust Header to be non Nul Terminated

file/include/logbook/logbook.hpp

@@ -99,9 +99,8 @@ namespace file
         {
           std::ifstream in(BASE_DIRECTORY LOGBOOK, std::ifstream::binary);
 
-          // File Header
           std::string ident = readString(in, 5);
-          if (ident.compare("VGAL") != 0) {
+          if (ident.compare(LOGBOOK_HEADER) != 0) {
             throw std::invalid_argument("Wrong file");
           }
           std::uint8_t version = read<std::uint8_t>(in);
@@ -129,8 +128,8 @@ namespace file
         inline void toFile() const
         {
           std::ofstream out(BASE_DIRECTORY LOGBOOK, std::fstream::binary);
-          char header[] = {'V', 'G', 'A', 'L', '\0', 1};
-          out.write(header, 6);
+          out.write(LOGBOOK_HEADER, 4);
+          out.write("\1", 1);
           for (const LogbookEntry &entry : this->entries) {
             entry.toFile(out);
           }