Replace fetch with Axios in client

Replace `.then` with await syntax where possible.

GitLab: #142
Change-Id: I6c132f49f152afa7e20919a1c70c539f2ad54878
diff --git a/client/src/pages/JamiRegistration.tsx b/client/src/pages/JamiRegistration.tsx
index a1024d5..62e59c1 100644
--- a/client/src/pages/JamiRegistration.tsx
+++ b/client/src/pages/JamiRegistration.tsx
@@ -74,14 +74,14 @@
       const accessToken = await loginUser(username, password);
       setAccessToken(accessToken);
       navigate('/settings', { replace: true });
-    } catch (err) {
+    } catch (e) {
       setIsCreatingUser(false);
-      if (err instanceof UsernameNotFound) {
+      if (e instanceof UsernameNotFound) {
         setErrorAlertContent(t('login_username_not_found'));
-      } else if (err instanceof InvalidPassword) {
+      } else if (e instanceof InvalidPassword) {
         setErrorAlertContent(t('login_invalid_password'));
       } else {
-        throw err;
+        throw e;
       }
     }
   };