Remove throw in the catch block

The throw statement in the catch won't be handled because
there is no higher level or top level error handler

Change-Id: I581a2a55747a97a04ac10c9befedc81f055c3ef6
diff --git a/client/src/pages/Login.tsx b/client/src/pages/Login.tsx
index 5887bb3..193497b 100644
--- a/client/src/pages/Login.tsx
+++ b/client/src/pages/Login.tsx
@@ -78,7 +78,7 @@
         } else if (e instanceof InvalidPassword) {
           setErrorAlertContent(t('login_invalid_password'));
         } else {
-          throw e;
+          setErrorAlertContent(t('unknown_error_alert'));
         }
       }
     }