fix: Delete hardcode (#1464)

### What problem does this PR solve?

After checking the language of the pdf, the line will hardcode the
language into Chinese

### Type of change

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

deepdoc/parser/pdf_parser.py

@@ -999,7 +999,6 @@ class RAGFlowPdfParser:
             self.is_english = True
         else:
             self.is_english = False
-        self.is_english = False
 
         st = timer()
         for i, img in enumerate(self.page_images):