Fix a bug for PollOnlyIfExecutorHasCapacity flag about pool size

[spmistry]

No description provided.

[coveralls]

Pull Request Test Coverage Report for Build 1061

• 0 of 1 (0.0%) changed or added relevant line in 1 file are covered.
• 2 unchanged lines in 2 files lost coverage.
• Overall coverage increased (+0.04%) to 71.211%

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Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
src/main/java/com/uber/cadence/internal/worker/PollTaskExecutor.java	0	1	0.0%

Files with Coverage Reduction	New Missed Lines	%
src/main/java/com/uber/cadence/internal/sync/WorkflowThreadContext.java	1	82.46%
src/main/java/com/uber/cadence/internal/worker/BlockCallerPolicy.java	1	62.5%

Totals
Change from base Build 1057:	0.04%
Covered Lines:	10839
Relevant Lines:	15221

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💛 - Coveralls