terminal-util: modernize terminal_reset_ansi_seq() a bit

Let's update the commentary a bit. Also, use a time-out of 100ms rather
than 50ms for this, simply to unify on the same value used in
vt_disallocate() in a similar case.

src/basic/terminal-util.c

@@ -583,9 +583,9 @@ static int terminal_reset_ansi_seq(int fd) {
                             "\033]104\007" /* reset colors */
                             "\033[?7h",    /* enable line-wrapping */
                             SIZE_MAX,
-                            50 * USEC_PER_MSEC);
+                            100 * USEC_PER_MSEC);
         if (k < 0)
-                log_debug_errno(k, "Failed to write to terminal: %m");
+                log_debug_errno(k, "Failed to reset terminal through ANSI sequences: %m");
 
         if (r > 0) {
                 r = fd_nonblock(fd, false);