(Fix) check address of Proxy smart-contract for validity

[mariano-aguero]

Closes #1042

How to test it and sections to check:

• Sections: crowdsale, contribute
• Create a crowdsale ,in the crowdsale section refresh the page and make sure it takes the parameter addr
• Create a crowdsale ,in the contribute section refresh the page and make sure it takes the parameter addr

[coveralls]

Pull Request Test Coverage Report for Build 2884

• 8 of 59 (13.56%) changed or added relevant lines in 6 files are covered.
• 7 unchanged lines in 3 files lost coverage.
• Overall coverage decreased (-0.09%) to 20.329%

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Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
src/components/manage/index.js	0	2	0.0%
src/utils/alerts.js	0	2	0.0%
src/utils/utils.js	5	11	45.45%
src/components/crowdsale/index.js	0	8	0.0%
src/components/contribute/index.js	0	9	0.0%
src/components/crowdsale/utils.js	3	27	11.11%
<!--	Total:	8	59	13.56%	-->

Files with Coverage Reduction	New Missed Lines	%
src/utils/utils.js	1	57.04%
src/components/contribute/index.js	3	0.0%
src/components/manage/index.js	3	0.0%
<!--	Total:	7		-->

Totals
Change from base Build 2857:	-0.09%
Covered Lines:	834
Relevant Lines:	3596

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💛 - Coveralls

[mariano-aguero]

@dennis00010011b

Crash after invalidCrowdsaleProxyAlert

Done