Correct Log repeat.

pymodbus/logging.py

@@ -150,7 +150,7 @@ def build_msg(cls, txt, *args):
         if not cls.repeat_log:
             cls.repeat_log = True
             return "Repeating...."
-        return cls.last_log_text
+        return None
 
     @classmethod
     def info(cls, txt, *args):

test/global/test_logging.py

@@ -1,4 +1,5 @@
 """Test datastore."""
+import contextlib
 import logging
 import os
 from unittest import mock
@@ -21,7 +22,8 @@ class TestLogging:
     def teardown_class(cls):
         """Remove test file."""
         if "CI" not in os.environ:  # pragma: no cover
-            os.remove(cls.LOG_FILE)
+            with contextlib.suppress(FileNotFoundError):
+                os.remove(cls.LOG_FILE)
 
     def test_log_dont_call_build_msg(self):
         """Verify that build_msg is not called unnecessary."""
@@ -117,6 +119,13 @@ def test_log_get_frames(self):
             Log.transport_dump(Log.SEND_DATA, b'678', b'9')
         pymodbus_get_last_frames()
 
+    def test_log_repeat(self):
+        """Test repeating log Frames."""
+        text = "msg being repeated."
+        assert text == Log.build_msg(text)
+        assert Log.build_msg(text) == "Repeating...."
+        assert not Log.build_msg(text)
+
     def test_transport_dump(self):
         """Test transport_dump."""
         pymodbus_apply_logging_config("error")