Fix Indexer post-compact hook logging of NPE and TableNotFound

The post-compact hook in the Indexer seems to log extraneous log messages indicating NPE or TableNotFound. The TableNotFound exceptions seem to indicate actual table names prefixed with MERGE or RESTORE, and sometimes suffixed with a digit, so perhaps these are views or something similar.
Examples:
2017-09-28 13:35:03,118 WARN [ctions-1506410238599] index.Indexer - Unable to permanently disable indexes being partially rebuild for SYSTEM.SEQUENCE
java.lang.NullPointerException
2017-09-28 10:20:56,406 WARN [ctions-1506410238415] index.Indexer - Unable to permanently disable indexes being partially rebuild for MERGE_PLATFORM_ENTITY.PLATFORM_IMMUTABLE_ENTITY_DATA2
org.apache.phoenix.schema.TableNotFoundException: ERROR 1012 (42M03): Table undefined. tableName=MERGE_PLATFORM_ENTITY.PLATFORM_IMMUTABLE_ENTITY_DATA2