Polish dy2st error message (#52527)

python/paddle/jit/dy2static/error.py

@@ -245,10 +245,16 @@ class ErrorData:
 
         # Simplify error value to improve readability if error is raised in runtime
         if self.in_runtime:
+            try:
                 if int(
-                os.getenv(SIMPLIFY_ERROR_ENV_NAME, DEFAULT_SIMPLIFY_NEW_ERROR)
+                    os.getenv(
+                        SIMPLIFY_ERROR_ENV_NAME, DEFAULT_SIMPLIFY_NEW_ERROR
+                    )
                 ):
                     self._simplify_error_value()
+            except:
+                pass
+            else:
                 message_lines.append(str(self.error_value))
                 return '\n'.join(message_lines)