add slash

Author: shuangela

config/redirects

@@ -8,4 +8,4 @@ symlink: current -> master
 
 raw: ${prefix}/ -> ${base}/current/
 raw: ${prefix}/master -> ${base}/upcoming/
-[v5.1-*]: ${prefix}/${version}/get-started/connect-to-mongodb -> ${base}/get-started/run-sample-query
+[v5.1-*]: ${prefix}/${version}/get-started/connect-to-mongodb -> ${base}/get-started/run-sample-query/