nexus-exam forgot to revert token refresh every hour (instead of every 30sec.!)

src/client/nexus-exam/nexus-exam.go

@@ -154,7 +154,7 @@ func refreshToken(parent fyne.Window) {
             u.Println(time.Now(), ": successfully refreshed token")
         }
         token = refreshedToken
-        time.Sleep(30*time.Second)
+        time.Sleep(1*time.Hour)
     }
 }