Remove commented code about Throw an exception if there is no location to fall back on

Issue on TODOs
Line 133 of LocationServiceImpl.java
Link: https://github.com/openmrs/openmrs-core/blob/1e84458acb17e00620cbce82f8ec1e5391f8d8f9/api/src/main/java/org/openmrs/api/impl/LocationServiceImpl.java#L133 contains this TODO:

Figure out if we should/could throw an exception if there's no location to fall back on.
if (location == null)

{ throw new APIException("Default location does not exist"); }