Changes the vaults so that ERC20 cannot leave governance

[aleph-v]

All paths which remove ERC20 from the system into the EOA are removed.

[coveralls]

Pull Request Test Coverage Report for Build 1779093293

• 4 of 4 (100.0%) changed or added relevant lines in 2 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage increased (+0.03%) to 94.068%

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Totals
Change from base Build 1761967531:	0.03%
Covered Lines:	499
Relevant Lines:	516

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💛 - Coveralls