Fix no-colour theme

In colour customization, pressing cancel ('ESC' by default) will
deselect all colours and put calcurse in no-color mode. For this
to work, all colour changes must be performed with the routines
custom_apply_attr()/custom_remove_attr(). Fixed for the getstring
cursor, the scroll window border and the week number.

In addition, the week number is unconditionally coloured as the
rest of the calendar contents whether CAL is selected or not.

Signed-off-by: Lukas Fleischer <lfleischer@calcurse.org>

src/getstring.c

@@ -69,8 +69,8 @@ static void getstr_print(WINDOW * win, int x, int y,
 	mvwprintw(win, y, col - 2, " %c", c);
 
 	/* print cursor */
-	wmove(win, y, st->ci[st->pos].dpyoff - st->ci[st->scrpos].dpyoff);
-	wchgat(win, 1, A_REVERSE, COLR_CUSTOM, NULL);
+	mvwaddch(win, y, st->ci[st->pos].dpyoff - st->ci[st->scrpos].dpyoff,
+		SPACE | A_REVERSE);
 }
 
 /* Delete a character at the given position in string. */