[SQL] Updated blocks table share_id to bigint

Will avoid issues with BIGINT from shares table getting too big for the
INT on the blocks share_id column.

Thanks IRC@webxassDE for the heads up!
Merge pull request #1882 from MPOS/blocks-share-id-bigint

[SQL] Updated blocks table share_id to bigint
Merge pull request #1 from MPOS/development

version update