Delete unnecessary "todo"

Case:
Some classes contain unnecessary "todo".

Example:

• DatabaseUtil class, line 95 - anonymous class removed (https://github.com/openmrs/openmrs-core/pull/2407) but "todo" is still there.

Solution:
Delete the unnecessary "todo".

Link to place in code for example class:
https://github.com/openmrs/openmrs-core/blob/master/api/src/main/java/org/openmrs/util/DatabaseUtil.java#L95