core: don't port collision detect UDP [GH-3859]

CHANGELOG.md

@@ -15,6 +15,7 @@ BUG FIXES:
       and should show less stale data. [GH-3808]
   - core: When setting a synced folder, it will assume it is not disabled
       unless explicitly specified. [GH-3783]
+  - core: Ignore UDP forwarded ports for collision detection. [GH-3859]
   - commands/package: Package with `--base` for VirtualBox doesn't
       crash. [GH-3827]
   - guests/windows: Private networks with static IPs work when there

lib/vagrant/action/builtin/handle_forwarded_port_collisions.rb

@@ -93,6 +93,11 @@ module Vagrant
             guest_port = options[:guest]
             host_port  = options[:host]
 
+            if options[:protocol] && options[:protocol] != "tcp"
+              @logger.debug("Skipping #{host_port} because UDP protocol.")
+              next
+            end
+
             if remap[host_port]
               remap_port = remap[host_port]
               @logger.debug("Remap port override: #{host_port} => #{remap_port}")