[Cin] in/out point selected plugin attach fix?

[Andrea paz]

Other tests:

Using Audio --> Attach Effect (con abilitato: "Single standalone and
shared others") in "Gang None", the plugin is applied to the first
master track only and applied as shared effects to all other armed
tracks, whether master or slave.

Using Audio --> Attach Effect in "Gang Media" (con abilitato: "Single
standalone and shared others"), the plugin is applied only to the
first armed master track and as shared effects to the following armed
slave tracks. A slave track preceding the first armed master track is
not taken into account.

Using Audio --> Attach Effect (with unchecked: "Single standalone and
shared others") in "Gang None", the plugin is applied to all armed
tracks, whether master or slaves. There are no shared effects, only
primary plugins.

Using Audio --> Attach Effect (with unchecked: "Single standalone and
shared others") in "Gang Media", the plugin is applied only to the
first armed master track and its slaves. A slave track preceding the
first armed master track is not taken into account. There are no
shared effects, only primary plugins.