org.openhab.io.console: fix build error with recent eclipse

Building the project org.openhab.io.console with recent eclipse (Luna) will
fail.

The project was not built since its build path is incomplete.
Cannot find the class file for org.eclipse.emf.ecore.resource.Resource$Diagnostic.
Fix the build path then try building this project.

The type org.eclipse.emf.ecore.resource.Resource$Diagnostic cannot be resolved.
It is indirectly referenced from required .class files
ConsoleInterpreter.java
/org.openhab.io.console/src/main/java/org/openhab/io/console
line 1