Remove redundant param of rewrite component. (#4422)

### What problem does this PR solve?

### Type of change

- [x] Bug Fix (non-breaking change which fixes an issue)

agent/component/rewrite.py

         super().__init__()
         self.temperature = 0.9
         self.prompt = ""
-        self.loop = 1
 
     def check(self):
         super().check()
     component_name = "RewriteQuestion"
 
     def _run(self, history, **kwargs):
-        if not hasattr(self, "_loop"):
-            setattr(self, "_loop", 0)
-        if self._loop >= self._param.loop:
-            self._loop = 0
-            raise Exception("Sorry! Nothing relevant found.")
-        self._loop += 1
-
         hist = self._canvas.get_history(4)
         conv = []
         for m in hist: