Fix typo in JavaConverters doc
Fix typo in JavaConverters doc

There is no such thing as scala.collection.mutable.concurrent.Map

    error: object concurrent is not a member of package scala.collection.mutable

Introduced in 2908236a

scala/scala,martijnhoekstra/scala,scala/scala,martijnhoekstra/scala,lrytz/scala,martijnhoekstra/scala,martijnhoekstra/scala,lrytz/scala,scala/scala,lrytz/scala,martijnhoekstra/scala,scala/scala,lrytz/scala,lrytz/scala,lrytz/scala,scala/scala,scala/scala,martijnhoekstra/scala