Fix (longstanding) gtk2 error, especially on OpenBSD
GTK2 apps crash during startup on OpenBSD due to a fatal [g_object_unref: assertion 'g_is_object (object)' failed] error. After long debugging, it became clear that the tooltip caused this error.
Adding AddToStyleWindow:=false solves the issue, also on other systems, that report this as only a warning.
if CompareText(WName,LazGtkStyleNames[lgsTooltip])=0 then
begin
AddToStyleWindow:=false; <-------------------------------- added !!