termptyesc: clearing the screen (from ED2) should not reset bottom margin

Thanks to @ncim for the report.

src/bin/termptyesc.c

@@ -1245,9 +1245,9 @@ _handle_esc_csi(Termpty *ty, const Eina_Unicode *c, const Eina_Unicode *ce)
         DBG("ED/DECSED %d: erase in display", arg);
         switch (arg)
           {
-           case TERMPTY_CLR_END:
-           case TERMPTY_CLR_BEGIN:
-           case TERMPTY_CLR_ALL:
+           case TERMPTY_CLR_END /* 0 */:
+           case TERMPTY_CLR_BEGIN /* 1 */:
+           case TERMPTY_CLR_ALL /* 2 */:
               termpty_clear_screen(ty, arg);
               break;
            case 3:

src/bin/termptyops.c

@@ -371,7 +371,6 @@ termpty_clear_screen(Termpty *ty, Termpty_Clear mode)
       case TERMPTY_CLR_ALL:
         ty->circular_offset = 0;
         termpty_cells_clear(ty, ty->screen, ty->w * ty->h);
-        ty->termstate.bottom_margin = 0;
         if (ty->cb.cancel_sel.func)
           ty->cb.cancel_sel.func(ty->cb.cancel_sel.data);
         break;