Update source constant for JVM driver versions) (#838)

Author: Chris Cho

snooty.toml

@@ -13,5 +13,5 @@ stable-api = "Stable API"
 csharp-version = "2.17"
 csharp-docs-versioned = "https://mongodb.github.io/mongo-csharp-driver/{+csharp-version+}"
 
-java-version = "4.6"
+java-version = "4.7"
 java-api = "https://mongodb.github.io/mongo-java-driver/{+java-version+}"