fix: cmdheight problems part3

Author: Shougo

src/nvim/message.c

@@ -2373,7 +2373,7 @@ bool msg_use_msgsep(void)
 {
   // the full-screen scroll behavior doesn't really make sense with
   // 'ext_multigrid'
-  return ((dy_flags & DY_MSGSEP) || ui_has(kUIMultigrid));
+  return (dy_flags & DY_MSGSEP) || ui_has(kUIMultigrid);
 }
 
 bool msg_do_throttle(void)

src/nvim/window.c

@@ -6415,12 +6415,6 @@ void command_height(void)
   // p_ch was changed in another tab page.
   curtab->tp_ch_used = p_ch;
 
-  // If the space for the command line is already more than 'cmdheight' there
-  // is nothing to do (window size must have decreased).
-  if (p_ch > old_p_ch && cmdline_row <= Rows - p_ch) {
-    return;
-  }
-
   // If cmdline_row is smaller than what it is supposed to be for 'cmdheight'
   // then set old_p_ch to what it would be, so that the windows get resized
   // properly for the new value.