confirm convict: use visible name to avoid exposing alternate identities

Ref #1593
See also:
https://www.reddit.com/r/dwarffortress/comments/ltzu82/if_i_wasnt_sure_i_found_the_vampire_before/
http://www.bay12forums.com/smf/index.php?topic=164123.msg8253738#msg8253738

docs/changelog.txt

@@ -33,6 +33,9 @@ changelog.txt uses a syntax similar to RST, with a few special sequences:
 
 # Future
 
+## Fixes
+- `confirm`: stopped exposing alternate names when convicting units
+
 ## Misc Improvements
 - `autohauler`: allow the ``Alchemist`` labor to be enabled in `manipulator` and other labor screens so it can be used for its intended purpose of flagging that no hauling labors should be assigned to a dwarf. Before, the only way to set the flag was to use an external program like Dwarf Therapist.
 - `embark-assistant`: slightly improved performance of surveying

plugins/lua/confirm.lua

@@ -211,7 +211,7 @@ function convict.intercept_key(key)
         screen.cur_column == df.viewscreen_justicest.T_cur_column.ConvictChoices
 end
 function convict.get_message()
-    name = dfhack.TranslateName(screen.convict_choices[screen.cursor_right].name)
+    name = dfhack.TranslateName(dfhack.units.getVisibleName(screen.convict_choices[screen.cursor_right]))
     if name == "" then
         name = "this creature"
     end