if you see something similar these, just press enter, or N,

Configuration file `/etc/pam.d/vsftpd'
==> File on system created by you or by a script.
==> File also in package provided by package maintainer.
What would you like to do about it ? Your options are:
Y or I : install the package maintainer's version
N or O : keep your currently-installed version
D : show the differences between the versions
Z : background this process to examine the situation
The default action is to keep your current version.
*** vsftpd (Y/I/N/O/D/Z) [default=N] ?

Configuration file `/etc/vsftpd.conf'
==> File on system created by you or by a script.
==> File also in package provided by package maintainer.
What would you like to do about it ? Your options are:
Y or I : install the package maintainer's version
N or O : keep your currently-installed version
D : show the differences between the versions
Z : background this process to examine the situation
The default action is to keep your current version.
*** vsftpd.conf (Y/I/N/O/D/Z) [default=N] ?