update zm-ews-stub jar version

[inpati]

Updated zm-zcs-lib ivy.xml and pkg-builder.pl, changed zm-ews-stub jar revision from 2.0 to 3.0.
This change is necessary as whenever we make changes in zm-ews-stub library we have to updated it's revision.

This changes shall be reviewed with old changes for zcs-4452

• https://github.com/Zimbra/zm-ews-stub/pull/5/commits/0eebbd143212c83bca8d3e888d7e73c211f71c86
• https://github.com/Zimbra/zm-ews-store/pull/40/commits/6b14ad3e9d594d041900500d1a929d474d0f6e45

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[BhavinBathani]

LGTM

[BhavinBathani]

Some additional thumb rules needs to be followed for commit message and branch-name:

• Commit message** Started with branch/issue name** Must be clear and to-the-point describing technical summery about change-set.

• Make sure branch names should be prefixed with issue-type.
  Following are some examples for branch names:** feature/PREAPPS-0000** bugfix/PREAPPS-0000** hotfix/PREAPPS-0000** release/PREAPPS-0000

[This applies to other relevant PRs as well]

[zimsuchitgupta]

LGTM