plug-ins: fix duplicate Brightness labels in Flame
After 3352fb86 there were 3 "Brightness" controls in Flame.
Two of them looks copy-pasted, so return them to their GIMP 2.10 strings. This also fixes messages about reusing accelerators.
After 3352fb86 there were 3 "Brightness" controls in Flame.
Two of them looks copy-pasted, so return them to their GIMP 2.10 strings. This also fixes messages about reusing accelerators.