Do not set the default values in the struct we're unmarshaling into

closes pterodactyl/panel#1786

If you set the defaults, you'll override a bunch of values for the server with the original values. For example this code caused servers in a running state to be changed to a non-running state, thus leading to stats not sending.

Just merge in any new values, leave everything else as empty.

server/update.go

@@ -3,7 +3,6 @@ package server
 import (
 	"encoding/json"
 	"github.com/buger/jsonparser"
-	"github.com/creasty/defaults"
 	"github.com/imdario/mergo"
 	"github.com/pkg/errors"
 	"go.uber.org/zap"
@@ -30,11 +29,6 @@ func (s *Server) UpdateDataStructure(data []byte, background bool) error {
 		return errors.New("attempting to merge a data stack with an invalid UUID")
 	}
 
-	// Set the default values in the interface that we unmarshaled into.
-	if err := defaults.Set(src); err != nil {
-		return errors.WithStack(err)
-	}
-
 	// Merge the new data object that we have received with the existing server data object
 	// and then save it to the disk so it is persistent.
 	if err := mergo.Merge(s, src, mergo.WithOverride); err != nil {