patch 8.1.1690: default padding for popup window menu is too much

Problem:    Default padding for popup window menu is too much.
Solution:   Only add padding left and right.
diff --git a/runtime/doc/popup.txt b/runtime/doc/popup.txt
index f74a7c2..0fd30eb 100644
--- a/runtime/doc/popup.txt
+++ b/runtime/doc/popup.txt
@@ -1,4 +1,4 @@
-*popup.txt*  For Vim version 8.1.  Last change: 2019 Jul 13
+*popup.txt*  For Vim version 8.1.  Last change: 2019 Jul 14
 
 
 		  VIM REFERENCE MANUAL    by Bram Moolenaar
@@ -362,7 +362,7 @@
 				\ drag: 1,
 				\ wrap: 0,
 				\ border: [],
-				\ padding: [],
+				\ padding: [0,1,0,1],
 				\ filter: 'popup_filter_menu',
 				\ })
 <		The current line is highlighted with a match using