elm_conformant: fix migration side effect

elm_conformant: fix migration side effect

Some apps can't show indicator regardless of indicator mode.
This patch fixes that bug.

test case:
1)
win = elm_win_add();
elm_win_indicator_mode_set(win, ELM_WIN_INDICATOR_SHOW);
elm_win_indicator_opacity_set(win, ELM_WIN_INDICATOR_OPAQUE);
conf = elm_conformant_add(win);
2)
win = elm_win_add();
conf = elm_conformant_add(win);
elm_win_indicator_mode_set(win, ELM_WIN_INDICATOR_SHOW);
elm_win_indicator_opacity_set(win, ELM_WIN_INDICATOR_OPAQUE);

Change-Id: Ieb83b089fa9d809ac66cbab87830a6c5031cc2b1