Fix error message in settings tab overlapping 'save' button

The save button is now fully functional again when an error message
is shown.

After an invalid value is entered in the settings tab dialog, the GUI
label for the error message that is shown was partly overlapping the
'save' button, so that the top half of the button could not be clicked
on.

builtin/mainmenu/tab_settings.lua

@@ -445,7 +445,7 @@ local function create_change_setting_formspec(dialogdata)
  if dialogdata.error_message then
  formspec = formspec .. "tablecolumns[color;text]" ..
  "tableoptions[background=#00000000;highlight=#00000000;border=false]" ..
- "table[5,4;5,1;error_message;#FF0000,"
+ "table[5,3.9;5,0.6;error_message;#FF0000,"
  .. core.formspec_escape(dialogdata.error_message) .. ";0]"
  width = 5
  if dialogdata.entered_text then