Fix API .htaccess file

Before it required an edit for osTicket installations made to a folder other
than the root of a domain or subdomain. Now, the installation path is
autodetected and rewritted.

Also, don't assume that every Apache installation has mod_rewrite support.

api/.htaccess

-RewriteEngine On
+<IfModule mod_rewrite.c>
 
-RewriteBase /api/
+RewriteEngine On
 
 RewriteCond %{REQUEST_FILENAME} !-f
 RewriteCond %{REQUEST_FILENAME} !-d
+RewriteCond %{REQUEST_URI} (.*/api)
+
+RewriteRule ^(.*)$ %1/http.php/$1 [L]
 
-RewriteRule ^(.*)$ http.php/$1 [L]
+</IfModule>