CLI: iOS build errors when trying to build with invalid native module

If you build for iOS and use a native "iphone" module that exists, but is missing the library file, the build errors while trying to show the error message. Plus the library file is being hashed before the check that it even exists.

Expected result:

• Should say the module is missing the library file

Actual result:

• The variable libFile is undefined

To test:

1. Create an app
2. Add an "iphone" module to the tiapp.xml
3. Go to the module's directory and rename the whatever.a file to whatever.a.bak
4. Build the app for iOS