You could do a reintall and get it generated.
Here is the (normal) content:
### SILVERSTRIPE START ###
<Files *.ss>
Order deny,allow
Deny from all
Allow from 127.0.0.1
</Files>
<IfModule mod_rewrite.c>
RewriteEngine On
RewriteBase /silverstripe
RewriteCond %{REQUEST_URI} !(\.gif$)|(\.jpg$)|(\.png$)|(\.css$)|(\.js$)
RewriteCond %{REQUEST_URI} ^(.*)$
RewriteCond %{REQUEST_FILENAME} !-f
RewriteRule .* sapphire/main.php?url=%1&%{QUERY_STRING} [L]
</IfModule>
### SILVERSTRIPE END ###
Of course RewriteBase /silverstripe has to be replaced by the place your install is.