Recover error connection

[congwang09]

Resolves: #355

If new domain joins, or domain status becomes "UP" again, sdx controller will go through all archived error connections, attempt to recover these connections.

[coveralls]

Pull Request Test Coverage Report for Build 23599494738

Details

• 5 of 81 (6.17%) changed or added relevant lines in 2 files are covered.
• 5 unchanged lines in 2 files lost coverage.
• Overall coverage decreased (-1.5%) to 52.283%

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Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
sdx_controller/handlers/lc_message_handler.py	0	20	0.0%
sdx_controller/handlers/connection_handler.py	5	61	8.2%

Files with Coverage Reduction	New Missed Lines	%
sdx_controller/handlers/connection_handler.py	2	58.35%
sdx_controller/handlers/lc_message_handler.py	3	13.86%

Totals
Change from base Build 23507366660:	-1.5%
Covered Lines:	1271
Relevant Lines:	2431

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💛 - Coveralls