etherscan: don't compress paths containing "contracts"

[SheldonHolmgren]

Partially fixes #150. After this patch slither successfully runs for 2 of the 3 addresses (0xcE4a49d7ed99C7c8746B713EE2f0C9aA631688d8 and 0x640022f8a9f00992fa63ee6bae25c2829deadd2d) mentioned in that issue. The other target still fails, this time with a different error (File outside of allowed directories instead of File not found.):

$ crytic-compile 0x2a311e451491091d2a1d3c43f4f5744bdb4e773a
...
ParserError: home/cluracan/code/0x-protocol/contracts/zero-ex/node_modules/@0x/contracts-erc20/contracts/src/v06/LibERC20TokenV06.sol:23:1: ParserError: Source "@0x/contracts-utils/contracts/src/v06/LibBytesV06.sol" not found: File outside of allowed directories.
import "@0x/contracts-utils/contracts/src/v06/LibBytesV06.sol";
^-------------------------------------------------------------^

[CLAassistant]

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[montyly]

Hi @SheldonHolmgren. Thank you for the contribution. We ended up taking a different approach with #345