patch 9.1.0464: no whitespace padding in commentstring option in ftplugins

Problem:  no whitespace padding in commentstring option in ftplugins
Solution: Change default to include whitespace padding, update
          existing filetype plugins with the new default value
          (Riley Bruins)

closes: #14843

Signed-off-by: Riley Bruins <ribru17@hotmail.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>
diff --git a/runtime/ftplugin/mma.vim b/runtime/ftplugin/mma.vim
index ce4cee1..91a8111 100644
--- a/runtime/ftplugin/mma.vim
+++ b/runtime/ftplugin/mma.vim
@@ -1,7 +1,8 @@
 " Vim filetype plugin file
 " Language:	Mathematica
 " Maintainer:	Ian Ford <ianf@wolfram.com>
-" Last Change:	22 January 2019
+" Last Change:	2019 Jan 22
+" 		2024 May 23 by Riley Bruins <ribru17@gmail.com> ('commentstring')
 
 " Only do this when not done yet for this buffer
 if exists("b:did_ftplugin")
@@ -13,4 +14,4 @@
 
 let b:undo_ftplugin = "setlocal commentstring<"
 
-setlocal commentstring=\(*%s*\)
+setlocal commentstring=\(*\ %s\ *\)