remove backslash from string to prevent syntax error in tsquery

wagtail/contrib/postgres_search/backend.py

@@ -228,7 +228,9 @@ class PostgresSearchQueryCompiler(BaseSearchQueryCompiler):
                 return self.get_search_field(sub_field_name, field.fields)
 
     def prepare_word(self, word):
-        return unidecode(word)
+        # remove backslash from string to prevent syntax error in tsquery
+        stripped_word = word.replace("\\", "") 
+        return unidecode(stripped_word)
 
     def build_tsquery_content(self, query, group=False):
         if isinstance(query, PlainText):