fix macro for sync all accounts

the macro for sync all accounts uses 'mbsync -a' command, which
failed to run for users who have moved their ~/.mbsyncrc somewhere
else.

we should use mw -Y instead, which can detect the MBSYNCRC env

share/mutt-wizard.muttrc

@@ -70,7 +70,7 @@ bind editor <Tab> complete-query
 
 macro index,pager a "<enter-command>set my_pipe_decode=\$pipe_decode pipe_decode<return><pipe-message>abook --add-email<return><enter-command>set pipe_decode=\$my_pipe_decode; unset my_pipe_decode<return>" "add the sender address to abook"
 macro index \Cr "T~U<enter><tag-prefix><clear-flag>N<untag-pattern>.<enter>" "mark all messages as read"
-macro index O "<shell-escape>mbsync -a<enter>" "run mbsync to sync all mail"
+macro index O "<shell-escape>mw -Y<enter>" "run mw -Y to sync all mail"
 macro index \Cf "<enter-command>unset wait_key<enter><shell-escape>printf 'Enter a search term to find with notmuch: '; read x; echo \$x >~/.cache/mutt_terms<enter><limit>~i \"\`notmuch search --output=messages \$(cat ~/.cache/mutt_terms) | head -n 600 | perl -le '@a=<>;s/\^id:// for@a;$,=\"|\";print@a' | perl -le '@a=<>; chomp@a; s/\\+/\\\\+/ for@a;print@a' \`\"<enter>" "show only messages matching a notmuch pattern"
 macro index A "<limit>all\n" "show all messages (undo limit)"