replication: dont declare variable in post-if scope

replication: dont declare variable in post-if scope

If a variable is defined and assigned in a conditional statement, it
is not defined behavior in Perl.

For more information about this behaviour see
https://perldoc.perl.org/perlsyn.html#Statement-Modifiers

> NOTE: The behaviour of a my, state, or our modified with a
> statement modifier conditional or loop construct (for example,
> `my $x if ...`) is undefined.
> The value of the my variable may be undef, any previously assigned
> value, or possibly anything else.
> Don't rely on it. Future versions of perl might do something
> different from the version of perl you try it out on. Here be
> dragons."

Signed-off-by: Thomas Lamprecht <t.lamprecht@proxmox.com>