Handle situation where users customized indicators incorrectly
Handle situation where users customized indicators incorrectly

Some users have included indeterminate values in their indicator lists
for objects that do not have indeterminate values (e.g., radio buttons).
The braille refactor didn't account for this.  This change permits their
incorrect code to still work.

chrys87/orca-beep,h4ck3rm1k3/orca-sonar,GNOME/orca,chrys87/orca-beep,pvagner/orca,chrys87/orca-beep,GNOME/orca,pvagner/orca,GNOME/orca,GNOME/orca,chrys87/orca-beep,h4ck3rm1k3/orca-sonar,pvagner/orca,h4ck3rm1k3/orca-sonar,pvagner/orca