set website default version to current stable (1.6) version (apache#1…

…8738)

* set website default version - test redirect

* enable first time redirect on all master website pages

* update test code

* remove unnecessary test code

* fix typo

* delete test code

docs/static_site/src/.htaccess

@@ -22,6 +22,12 @@ RewriteOptions AllowNoSlash
 
 </IfModule>
 
+# Set default website version to current stable (v1.6)
+RewriteCond %{REQUEST_URI} !^/versions/
+RewriteCond %{HTTP_REFERER} !mxnet.apache.org
+RewriteCond %{HTTP_REFERER} !mxnet.incubator.apache.org
+RewriteRule ^(.*)$ /versions/1.6/$1 [r=307,L]
+
 # TODO temporary fix for issue #18604
 Redirect 302 /api/r/docs/api/R-package/build/mxnet-r-reference-manual.pdf https://mxnet-public.s3.us-east-2.amazonaws.com/docs/v1.x/mxnet-r-reference-manual.pdf
 Redirect 302 /api/scala/docs/api/ /versions/1.6/api/scala/docs/api/