nedmail: don't try to shoot down subcommand on interrupt

this breaks interrupt key handling in rio. theres also no
point in trying todo so as rio sends the note to the whole
process group so the subcommand should have got the note
already.

just wait for the subprocess to terminate.

sys/src/cmd/upas/ned/nedmail.c

@@ -2593,9 +2593,7 @@ fqcmd(Cmd*, Message *m)
 void
 system(char *cmd, char **av, int in)
 {
-	int pid;
-
-	switch(pid=fork()){
+	switch(fork()){
 	case -1:
 		return;
 	case 0:
@@ -2615,7 +2613,7 @@ system(char *cmd, char **av, int in)
 		while(waitpid() < 0){
 			if(!interrupted)
 				break;
-			postnote(PNPROC, pid, "die");
+			interrupted = 0;
 			continue;
 		}
 		break;