Merge pull request #2827 in HDFFV/hdf5 from ~BYRN/hdf5_adb:hdf5_1_12 to hdf5_1_12
* commit 'e31653cf5f547d4d8baff7be40f3b1b69b1765c5':
Revert H5_VERS_SUBRELEASE check
Add special case when H5_VERS_SUBRELEASE is 0
Condition if (H5_VERS_SUBRELEASE) is incorrectly false when H5_VERS_SUBRELEASE is 0, a valid value for H5_VERS_SUBRELEASE. Updated to if (${H5_VERS_SUBRELEASE} STREQUAL "") with corresponding reversal of action statements to avoid NOT.
Add hypen to subrelease regex
Add ifdef blocks to S3/HDFS test
