fix local disk migration when no target storage is set

fix local disk migration when no target storage is set

the check for targetstorage in:
if ($self->{running} && $self->{opts}->{targetstorage} && $local_volumes->{$volid}->{ref} eq 'config') {

was obsolete, as we always set the tragetstorage opts variable to '1'
in a broader "use same sid for remote local" check above.
So removing it leads to the same if truthtable but fixes the
check if we should fallback to the volume's SID if targetstorage is
not set, as else it seemed to be always set, and '1' is naturally not
a correct stroage ID.

Signed-off-by: Thomas Lamprecht <t.lamprecht@proxmox.com>
Signed-off-by: Wolfgang Bumiller <w.bumiller@proxmox.com>