Added CFLAGS -Wall -Wextra to configure.ac

Fixed some compiler warnings related to changed CFLAGS settings.

src/utils.c

@@ -317,7 +317,7 @@ sock_open(int *fd, int port, int localhost)
 	struct sockaddr_in sock;
 
 	*fd = socket(PF_INET, SOCK_STREAM, 0);
-	err_ret_if(fd < 0, -1);
+	err_ret_if(*fd < 0, -1);
 
 	/* todo: verify if this realy work */
 	/* prevent "Error Address already in use" error message */