Fix makefile: use ifneq instead of ifndef

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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=151622898

Increment minor version to 2.9 to prepare for a new release.

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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=148830554

Increment minor version of Java Cloud Debugger

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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=111559500

Update Java Cloud Debugger to v2.2