kernel/v2: clear ID field so its not passed to provisioner [GH-3424]

CHANGELOG.md

@@ -14,6 +14,7 @@ BUG FIXES:
   - core: `vagrant` on Windows cmd.exe doesn't always exit with exit
       code zero. [GH-3420]
   - core: Adding a box from a network share has nice error on Windows. [GH-3279]
+  - core: Setting an ID on a provisioner now works. [GH-3424]
   - commands/package: Nice error if includes contain symlinks. [GH-3200]
   - commands/rsync-auto: Don't crash if the machine can't be communicated
       to. [GH-3419]

plugins/kernel_v2/config/vm.rb

@@ -252,15 +252,15 @@ module VagrantPlugins
       end
 
       def provision(name, **options, &block)
-        options[:id] = options[:id].to_s if options[:id]
+        id = options.delete(:id).to_s if options.has_key?(:id)
 
         prov = nil
-        if options[:id]
-          prov = @provisioners.find { |p| p.id == options[:id] }
+        if id
+          prov = @provisioners.find { |p| p.id == id }
         end
 
         if !prov
-          prov = VagrantConfigProvisioner.new(options[:id], name.to_sym)
+          prov = VagrantConfigProvisioner.new(id, name.to_sym)
           @provisioners << prov
         end