tdf#92266 better language selection in Windows installer

It won't select 'kok' when we have 'ko', 'sid' when we have
'si', but language variants will fall back, e.g. en_ZW -> en.

Change-Id: Ie417b6be664d5148829d2f7280e20653f84bc7a3
Reviewed-on: https://gerrit.libreoffice.org/28744Reviewed-by: Andras Timar <andras.timar@collabora.com>
Tested-by: Andras Timar <andras.timar@collabora.com>

setup_native/source/win32/customactions/sellang/sellang.cxx

@@ -185,8 +185,13 @@ static BOOL
 present_in_ui_langs(const char *lang)
 {
     for (int i = 0; i < num_ui_langs; i++)
-        if (memcmp (ui_langs[i], lang, std::min(strlen(ui_langs[i]), strlen(lang))) == 0)
+    {
+        if (strchr (lang, '_') != NULL)
+            if (memcmp (ui_langs[i], lang, std::min(strlen(ui_langs[i]), strlen(lang))) == 0)
+                return TRUE;
+        if (strcmp (ui_langs[i], lang) == 0)
             return TRUE;
+    }
     return FALSE;
 }