Add better default password security

https://forum.virtualmin.com/t/good-secure-passwords-ready-to-use-for-installation/132552

Author: iliajie

Diff for: config.info

@@ -76,7 +76,7 @@ mail_skel=Initial files directory for mail users,3,None
 proxy_pass=Allow creation of forwarding-only websites?,1,1-Yes using proxying,2-Yes using frame forwarding,0-No
 homes_dir=Subdirectory for mailbox user home directories,0,20
 passwd_mode=Password field type,1,1-Randomly generated password,0-Enter password once,2-Enter password twice
-passwd_length=Length of randomly generated password,3,Default (15 characters),5
+passwd_length=Length of randomly generated password,3,Default (25 characters),5
 passwd_chars=Characters for random passwords,3,Default (A-Z, a-z, 0-9)
 limitnoalias=Include alias servers in limits?,1,0-Yes,1-No
 username_length=Maximum length for automatically generated usernames,3,Unlimited

Diff for: virtual-server-lib-funcs.pl

@@ -11402,7 +11402,7 @@ sub random_password
 &seed_random();
 &require_useradmin();
 my $random_password;
-my $len = $_[0] || $config{'passwd_length'} || 15;
+my $len = $_[0] || $config{'passwd_length'} || 25;
 eval "utf8::decode(\$config{'passwd_chars'})"
 	if ($config{'passwd_chars'});
 my @passwd_chars = split(//, $config{'passwd_chars'});