samples: http_server: Fix warning about integer name

When building with CONFIG_DEBUG=y, there is a build warning about the
name being truncated due to integer size is larger than MAX_NAME_LEN. So
fix with modulo operator to be clear to the compiler what we expect.

Signed-off-by: Declan Snyder <declan.snyder@nxp.com>

Author: decsny

samples/net/sockets/http_server/src/ws.c

@@ -324,7 +324,7 @@ int ws_echo_setup(int ws_socket, struct http_request_ctx *request_ctx, void *use
 #define MAX_NAME_LEN sizeof("ws[xx]")
 		char name[MAX_NAME_LEN];
 
-		snprintk(name, sizeof(name), "ws[%d]", slot);
+		snprintk(name, sizeof(name), "ws[%d]", slot % (10 * MAX_NAME_LEN));
 		k_thread_name_set(&ws_handler_thread[slot], name);
 	}