pmgbackup: fix missing semicolon leading to weird effects

pmgbackup: fix missing semicolon leading to weird effects

without as semicolon the code run at "compile" (initial parse) time,
not after that. Thus, every code error was attributed to an
compilation error, i.e., bad syntax or the like, not a runtime die.

This was visible as the program executed when using perl check
> # perl -wc src/bin/pmgbackup

which should normally not be the case

Originally-by: Stoiko Ivanov <s.ivanov@proxmox.com>
Signed-off-by: Thomas Lamprecht <t.lamprecht@proxmox.com>