Fix warnings about thread.setDaemon() in python 3.10+

easy_train.py:316: DeprecationWarning: setDaemon() is deprecated,
set the daemon attribute instead thread.setDaemon(True)

camelCase methods in threading were deprecated in:
python/cpython#25174

scripts/easy_train.py

@@ -313,7 +313,7 @@ def f():
         os._exit(errcode)
 
     thread = Thread(target=f)
-    thread.setDaemon(True)
+    thread.daemon = True
     thread.start()
 
 if sys.platform == "win32":
@@ -499,7 +499,7 @@ def __init__(self, period_seconds):
         self._running = True
         self._update()
 
-        self.setDaemon(True)
+        self.daemon = True
         self.start()
 
     def _update(self):
@@ -2410,7 +2410,7 @@ def f():
             time.sleep(1)
 
     thread = Thread(target=f)
-    thread.setDaemon(True)
+    thread.daemon = True
     thread.start()
 
 def main():