[apps/global_preferences] DefaultLanguage is the first of the locales

Not EN, because we might build without the EN locale

apps/global_preferences.h

@@ -25,8 +25,9 @@ public:
   void setFont(const KDFont * font) { m_font = font; }
   constexpr static int NumberOfBrightnessStates = 5;
 private:
+  static_assert(I18n::NumberOfLanguages > 0, "I18n::NumberOfLanguages is not superior to 0"); // There should already have be an error when processing an empty EPSILON_I18N flag
   GlobalPreferences() :
-    m_language(I18n::Language::EN),
+    m_language((I18n::Language)0),
     m_examMode(ExamMode::Unknown),
     m_showPopUp(true),
     m_brightnessLevel(Ion::Backlight::MaxBrightness),

apps/i18n.py

@@ -95,8 +95,10 @@ def print_header(data, path, locales):
 
     # Languages enumeration
     f.write("enum class Language : uint16_t {\n")
+    index = 0
     for locale in locales:
-        f.write("  " + locale.upper() + ",\n")
+        f.write("  " + locale.upper() + (" = 0" if (index < 1) else "") +",\n")
+        index = index + 1
     f.write("};\n\n")
 
     # Language names