Wrong default bouldering scale for Polish grade context

[sviatoslavsaviak]

When you input a bouldering difficulty without a letter (5 or 5+ instead of 5a, 5b+...) in the Polish grade context, theCrag automatically considers it to be the FR_ALT grading system, which is not used in Poland. Instead, it should be treated as the regular Fontainebleau grading system.