changed an error message to make it slightly more clear

pyflowery/pyflowery.py

@@ -113,7 +113,7 @@ class FloweryAPI:
         """
         if len(text) > 2048:
             if not self.config.allow_truncation:
-                raise ValueError('Text must be less than 2048 characters')
+                raise ValueError('Text must be less than or equal to 2048 characters')
             self.config.logger.warning('Text is too long, will be truncated to 2048 characters by the API')
         params = {
             'text': text,