Bundler: Fix a path computation.

The bundler recognizes json config files based on the input host-name as follows:

baseName = Path.GetFileNameWithoutExtension(hostName).
depsJsonName = baseName + "deps.json"
On Linux, since executables don't have an .exe extension, this logic is incorrect for apps whose name contains a . in their name.
For example, if hostName is Some.App, depsJson is incorrectly computed as Some.deps.json instead of Some.App.deps.json.

This change fixes the problem.