private static String getConfigId(String configId) {
        if (configId.startsWith("file:") || configId.startsWith("dir:")) {
            return "";
        } else {
            return configId;
        }
    }
A Config URI is a class that can be used to encapsulate a config source and a config id into one
object to simplify parameter passing.

@author Ulf Lilleengen
config/src/main/java/com/yahoo/config/subscription/ConfigURI.java