vagrafile: switch to bionic

git-svn-id: https://svn.osgeo.org/grass/grass/trunk@73294 15284696-431f-4ddb-bdfa-cd5b030d7da7

Vagrantfile

@@ -13,10 +13,10 @@ Vagrant.configure(VAGRANTFILE_API_VERSION) do |config|
   vm_ram = ENV['VAGRANT_VM_RAM'] || 1024
   vm_cpu = ENV['VAGRANT_VM_CPU'] || 1
   
-  config.vm.box = "xenial64"
+  config.vm.box = "bionic64"
   
   config.vm.hostname = "grass-gis-vagrant"
-  config.vm.box_url = "https://cloud-images.ubuntu.com/xenial/current/xenial-server-cloudimg-amd64-vagrant.box"
+  config.vm.box_url = "https://cloud-images.ubuntu.com/bionic/current/bionic-server-cloudimg-amd64-vagrant.box"
   config.vm.define "grass-gis-vagrant" do |host|
     
     config.vm.network :forwarded_port, guest: 80, host: 8080

gui/wxpython/gui_core/ghelp.py

@@ -31,7 +31,7 @@ else:
     _unichr = chr
 
 import wx
-from wx.html import HtmlWindow
+from wx.html2 import WebView as HtmlWindow
 try:
     from wx.lib.agw.hyperlink import HyperLinkCtrl
 except ImportError: