Remove master transport client docs (#900)

Author: lcawl

conf.yaml

@@ -317,7 +317,7 @@ contents:
                 title:      Java API
                 prefix:     java-api
                 current:    7.1
-                branches:   [ master, 7.x, 7.2, 7.1, 7.0, 6.8, 6.7, 6.6, 6.5, 6.4, 6.3, 6.2, 6.1, 6.0, 5.6, 5.5, 5.4, 5.3, 5.2, 5.1, 5.0, 2.4, 2.3, 2.2, 2.1, 2.0, 1.7, 1.6, 1.5, 1.4, 1.3, 0.90 ]
+                branches:   [ 7.x, 7.2, 7.1, 7.0, 6.8, 6.7, 6.6, 6.5, 6.4, 6.3, 6.2, 6.1, 6.0, 5.6, 5.5, 5.4, 5.3, 5.2, 5.1, 5.0, 2.4, 2.3, 2.2, 2.1, 2.0, 1.7, 1.6, 1.5, 1.4, 1.3, 0.90 ]
                 index:      docs/java-api/index.asciidoc
                 tags:       Clients/Java
                 subject:    Clients