Remove unneded exception handler from has_alpha()

src/paperless_tesseract/parsers.py

@@ -67,14 +67,8 @@ class RasterisedDocumentParser(DocumentParser):
         ]
 
     def has_alpha(self, image):
-        try:
         with Image.open(image) as im:
             return im.mode in ('RGBA', 'LA')
-        except Exception as e:
-            self.log(
-                'warning',
-                f"Error while check for alpha channel in image {image}: {e}")
-            return None
 
     def get_dpi(self, image):
         try: