FTI policy: When determining whether to close a bug, only see other FTI trackers
The FTBFS trackers are not handled by this script (yet),
so the bugs would remain open until closed manually.
Given that a fix of FTI anticipates a rebuild (in the vast majority of cases),
a fixed FTI ~=> a fixed FTBFS.
Note that the relevant logic to determine whether to close a bug is:
if not ({BLOCKERS} - {FxxFailsToInstall}) & {TRACKERS})
Signed-off-by: Miro Hrončok <miro@hroncok.cz>