changed GPG parameters from -q to --quiet

under Qubes OS the use of qubes-gpg-client (instead of gpg) will not work with the -q option, but with the --quiet option.
As such using the full parameter names will not harm to all "normal" users, but make the script more stable for other users.
Additionaly it makes the scripts more readable for beginners to understand what the script is doing.

credentials/getmuttpass

@@ -1,4 +1,4 @@
 #!/bin/bash
-pass=$(gpg2 -d -q ~/.config/mutt/credentials/$1.gpg)
+pass=$(gpg2 --decrypt --quiet ~/.config/mutt/credentials/$1.gpg)
 echo set smtp_pass=\"$pass\"
 echo set imap_pass=\"$pass\"