Fix old l4g references

utils/license.go

@@ -17,7 +17,7 @@ import (
 	"strconv"
 	"strings"
 
-	l4g "code.google.com/p/log4go"
+	l4g "github.com/alecthomas/log4go"
 
 	"github.com/mattermost/platform/model"
 )