Fix checking possibly unset option.

Error printed to console is:

    AttributeError: 'Options' object has no attribute 'enable_emphasis'
    Exception occurred: 'Options' object has no attribute 'enable_emphasis'

Ref: kabachuha#243

scripts/modelscope/clip_hardcode.py

@@ -150,7 +150,7 @@ def tokenize_line(self, line):
         Returns the list and the total number of tokens in the prompt.
         """
 
-        if opts.enable_emphasis:
+        if hasattr(opts, 'enable_emphasis') and opts.enable_emphasis:
             parsed = prompt_parser.parse_prompt_attention(line)
         else:
             parsed = [[line, 1.0]]