logind: do not emit beep in wall messages

Those may go via the PC speaker, which is annoying and unexpected.
Most people have it off, so this doesn't work reliably anyway, so we can
disable it without much loss.

Fixes #23520.

(cherry picked from commit ef3458cd5dc8d5b400c9abbea92986c43aef18cc)
(cherry picked from commit 3e38c39600dcc0b54b05a870937e57f08dfdc679)

src/shared/utmp-wtmp.c

@@ -360,7 +360,7 @@ int utmp_wall(
         }
 
         if (asprintf(&text,
-                     "\a\r\n"
+                     "\r\n"
                      "Broadcast message from %s@%s%s%s (%s):\r\n\r\n"
                      "%s\r\n\r\n",
                      un ?: username, hn,