[lbry] claimtrie: more verbose error message in ResetHeight

[roylee17]

Print out if RramTrie was fully rebuilt during claimtrie.ResetHeight() to help triage the issue #71

[coveralls]

Pull Request Test Coverage Report for Build 2686483495

• 5 of 9 (55.56%) changed or added relevant lines in 1 file are covered.
• 16 unchanged lines in 4 files lost coverage.
• Overall coverage decreased (-0.03%) to 51.839%

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Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
claimtrie/claimtrie.go	5	9	55.56%

Files with Coverage Reduction	New Missed Lines	%
claimtrie/claimtrie.go	1	75.21%
connmgr/connmanager.go	2	85.36%
btcec/signature.go	3	92.82%
peer/peer.go	10	75.53%

Totals
Change from base Build 2673585093:	-0.03%
Covered Lines:	22453
Relevant Lines:	43313

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💛 - Coveralls