Don't use StandardPaths before OnInit is called

AegisubLocale is created extremely early in the application
initialization, and using StandardPaths in its constructor resulted in
?user being set to an incorrect value as the app name hadn't been set
yet.

aegisub/src/aegisublocale.cpp

@@ -56,13 +56,17 @@
 #define AEGISUB_CATALOG "aegisub"
 #endif
 
-AegisubLocale::AegisubLocale() {
-	wxTranslations::Set(new wxTranslations);
+wxTranslations *AegisubLocale::GetTranslations() {
+	wxTranslations *translations = wxTranslations::Get();
+	if (!translations) {
+		wxTranslations::Set(translations = new wxTranslations);
 		wxFileTranslationsLoader::AddCatalogLookupPathPrefix(StandardPaths::DecodePath("?data/locale/"));
 	}
+	return translations;
+}
 
 void AegisubLocale::Init(wxString const& language) {
-	wxTranslations *translations = wxTranslations::Get();
+	wxTranslations *translations = GetTranslations();
 	translations->SetLanguage(language);
 	translations->AddCatalog(AEGISUB_CATALOG);
 	translations->AddStdCatalog();
@@ -73,7 +77,7 @@ void AegisubLocale::Init(wxString const& language) {
 }
 
 wxString AegisubLocale::PickLanguage() {
-	wxArrayString langs = wxTranslations::Get()->GetAvailableTranslations(AEGISUB_CATALOG);
+	wxArrayString langs = GetTranslations()->GetAvailableTranslations(AEGISUB_CATALOG);
 	langs.insert(langs.begin(), "en_US");
 
 	// Check if user local language is available, if so, make it first

aegisub/src/aegisublocale.h

@@ -34,6 +34,8 @@
 /// @ingroup utility
 ///
 
+class wxTranslations;
+
 /// DOCME
 /// @class AegisubLocale
 /// @brief DOCME
@@ -41,8 +43,8 @@
 /// DOCME
 class AegisubLocale {
 	wxString active_language;
+	wxTranslations *GetTranslations();
 public:
-	AegisubLocale();
 	void Init(wxString const& language);
 	wxString PickLanguage();
 };