Fixed issue# 766 

Avoid search of private notebooks.
I got paranoid and thought its a kind of standard which is followed in code to evaluate isTRUE(TRUE). IN Rcloud.support.R 
already at line 126 its used  if(isTRUE(l[[1]] == "tmpfile")). There are many places where it is used in our codebase.
Ref:http://rfunction.com/archives/2094