server : Support listening on a unix socket (#12613)

* server : Bump cpp-httplib to include AF_UNIX windows support

Signed-off-by: Piotr Stankiewicz <piotr.stankiewicz@docker.com>

* server : Allow running the server example on a unix socket

Signed-off-by: Piotr Stankiewicz <piotr.stankiewicz@docker.com>

---------

Signed-off-by: Piotr Stankiewicz <piotr.stankiewicz@docker.com>

Author: Piotr

common/arg.cpp

@@ -1979,7 +1979,7 @@ common_params_context common_params_parser_init(common_params & params, llama_ex
     ).set_examples({LLAMA_EXAMPLE_EMBEDDING}));
     add_opt(common_arg(
         {"--host"}, "HOST",
-        string_format("ip address to listen (default: %s)", params.hostname.c_str()),
+        string_format("ip address to listen, or bind to an UNIX socket if the address ends with .sock (default: %s)", params.hostname.c_str()),
         [](common_params & params, const std::string & value) {
             params.hostname = value;
         }