make escape sequence to exit tty optional

We want to reuse lxc_console_cb_tty_stdin() in lxc_attach.c.

Signed-off-by: Christian Brauner <christian.brauner@mailbox.org>

src/lxc/console.c

@@ -641,16 +641,19 @@ static int lxc_console_cb_tty_stdin(int fd, uint32_t events, void *cbdata,
 		return 1;
 	}
 
-	/* we want to exit the console with Ctrl+a q */
-	if (c == ts->escape && !ts->saw_escape) {
-		ts->saw_escape = 1;
-		return 0;
-	}
+	if (ts->escape != -1) {
+		/* we want to exit the console with Ctrl+a q */
+		if (c == ts->escape && !ts->saw_escape) {
+			ts->saw_escape = 1;
+			return 0;
+		}
 
-	if (c == 'q' && ts->saw_escape)
-		return 1;
+		if (c == 'q' && ts->saw_escape)
+			return 1;
+
+		ts->saw_escape = 0;
+	}
 
-	ts->saw_escape = 0;
 	if (write(ts->masterfd, &c, 1) < 0) {
 		SYSERROR("failed to write");
 		return 1;