Fix syntax

Author: Daltz333

source/_extensions/pwa_service.py

@@ -59,7 +59,7 @@ def get_files_to_cache(outDir: str, config: Dict[str, Any]):
 
                 # enables RTD multilanguage support
                 if os.getenv("READTHEDOCS"):
-                    url = urljoin(parse_result.netloc, os.getenv("READTHEDOCS_LANGUAGE"), os.getenv("READTHEDOCS_PROJECT"))
+                    url = parse_result.netloc + os.getenv("READTHEDOCS_LANGUAGE") + "/" + os.getenv("READTHEDOCS_VERSION") + "/"
 
             if config["html_baseurl"] is None and not os.getenv("CI"):
                 logger.warning(

source/_extensions/pwa_service_files/sw.js

@@ -14,8 +14,8 @@ self.addEventListener('install', function (e) {
             await addKeys(tofetch)
           }
         })
-        .catch(error => {
-          console.error(error);
+        .catch((error) => { {
+          console.error(error.message);
         });
   }());
 });