guardiand v2.7.3

New features:

• Add re-observation support for Ethereum and Terra (#839, #835, #834).

Improvements:

• Polygon now requires a minimum of 512 confirmations, up from 256 (#829). This is done as a precautionary measure in response to a recent series of very large rollbacks on Polygon (polygonscan.com/blocks_forked).
• Fix a slow memory leak (#782).
• Fix VAA injection for core bridge governance messages (#814).
• We now bail on on failed transactions earlier, lowering RPC request rate (#821).