Warn if the NRO has no icon instead of crashing

nton/main.py

@@ -264,11 +264,16 @@ def build(
         else:
             icon_file_res = nstool.get_icon(path, icon_file)
             if icon_file_res:
+                if icon_file_res == "No Icon was extracted from the asset.":
+                    log.warning("The NRO does not have an Icon, proceeding without one.")
+                else:
                     log.critical(f"Failed extracting the Icon partition from the NRO, {icon_file_res}")
                     sys.exit(2)
+            else:
                 log.debug("Got the Icon partition")
                 log.debug(base64.b64encode(icon_file.read_bytes()).decode())
 
+        if icon_file.exists():
             # We must strip every unnecessary metadata or the icon will be a '?'
             try:
                 subprocess.check_output([