Set alarm for extended options.

Instead of clearing the alarm, set it to two seconds;
Previously, this could, potentially, not finish at all on some telnet
clients, which is definitely bad. This is a reasonable workaround.

src/nyancat.c

@@ -443,14 +443,14 @@ int main(int argc, char ** argv) {
 							if (sb[0] == TTYPE) {
 								/* This was a response to the TTYPE command, meaning
 								 * that this should be a terminal type */
-								alarm(0);
+								alarm(2);
 								strcpy(term, &sb[2]);
 								done++;
 							}
 							else if (sb[0] == NAWS) {
 								/* This was a response to the NAWS command, meaning
 								 * that this should be a window size */
-								alarm(0);
+								alarm(2);
 								terminal_width = sb[2];
 								done++;
 							}