debugger: don't override module binding
debugger: don't override module binding

Overriding module argument with const causes a SyntaxError. This
commit changes the variable name to remove the error.

PR-URL: https://github.com/iojs/io.js/pull/572
Reviewed-By: Colin Ihrig <838f779c91673db29b8572ea3f54d191d3878ae2@gmail.com>

dreamllq/node,dreamllq/node,dreamllq/node,dreamllq/node,dreamllq/node,dreamllq/node,dreamllq/node,dreamllq/node,dreamllq/node