Duke3D: Fix crash when loading addon descriptors with no CFG present

Will now check if scriptfile is present when trying to load the addon
activation status or the load order from the config.

source/duke3d/src/config.cpp

@@ -1133,6 +1133,10 @@ int CONFIG_SetMapBestTime(uint8_t const * const mapmd4, int32_t tm)
 int32_t CONFIG_GetAddonActivationStatus(const char* addonIdentifier)
 {
     int32_t status = 0;
+
+    if (!ud.config.setupread || ud.config.scripthandle < 0)
+        return status;
+
     SCRIPT_GetBoolean(ud.config.scripthandle, "Active Addons", addonIdentifier, &status);
     return status;
 }
@@ -1140,6 +1144,10 @@ int32_t CONFIG_GetAddonActivationStatus(const char* addonIdentifier)
 int32_t CONFIG_GetAddonLoadOrder(const char* addonIdentifier)
 {
     int32_t loadOrder = -1;
+
+    if (!ud.config.setupread || ud.config.scripthandle < 0)
+        return loadOrder;
+
     if (SCRIPT_GetNumber(ud.config.scripthandle, "TC Load Order", addonIdentifier, &loadOrder))
         SCRIPT_GetNumber(ud.config.scripthandle, "Mod Load Order", addonIdentifier, &loadOrder);
     return loadOrder;