DOP-1883: use correct base URL for phplib sitemap (#22)

Author: schmalliso

conf-sitemap.xml

@@ -1,13 +1,13 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <site
-  base_url="https://docs.mongodb.com/php-library/"
+  base_url="https://docs.mongodb.com/php-library/current/"
   store_into="build/master/sitemap.xml.gz"
   verbose="1"
   >
 
 <directory
 	path="build/public/"
-	url="https://docs.mongodb.com/php-library/"
+	url="https://docs.mongodb.com/php-library/current/"
 	default_file="index.html"
 	/>
 <filter  action="drop"  type="wildcard"  pattern="*~" />