no check on llm_context_create() options

[danielebriggi]

Options like this one n_ctx=5000context_size=5000 (without comma , separation) does not raise error.
Tested on llm_context_create() function only.

[andinux]

I'm not sure it should rise an error, what do you think @marcobambini ?

This option string is internally parsed as

key=n_ctx
value=5000context_size=5000

then the following code extracts the long int value from the value string, setting options->n_ctx to 5000 and discarding the following chars.

if (strncasecmp(key, OPTION_KEY_N_CTX, key_len) == 0) {
        int value = (int)strtol(buffer, NULL, 0);
        if (value >= 0) options->n_ctx = value;
        return true;
    }