ecore_imf/wayland: Only call hide_input_panel on im_context_hide().

There's no need to call it on text_input_leave too, otherwise this would
be called twice, the one from text_input_leave possibly being called
after the focus was regain already by a text input, causing the bug
described in T237.

This fixes T237.

src/modules/ecore_imf/wayland/wayland_imcontext.c

@@ -512,9 +512,6 @@ text_input_leave(void                 *data,
 {
    WaylandIMContext *imcontext = (WaylandIMContext *)data;
 
-   if (text_input)
-     wl_text_input_hide_input_panel(text_input);
-
    /* clear preedit */
    commit_preedit(imcontext);
    clear_preedit(imcontext);