GEANY_BCS_PROJ_FT doesn't get used for GEANY_GBG_FT in get_next_build_cmd
With #2307, I think GEANY_BCS_PROJ_FT can be removed and we just use GEANY_BCS_PROJ.
Also in get_next_build_cmd: for the filetype build group, GEANY_BCS_PREF is used for `ftp->homefilecmds`. Shouldn't that correspond to GEANY_BCS_HOME_FT, as it does in get_build_group_pointer?