Fix #5052: Guard potentially undefined e_PAGE constant

[Deltik]

Motivation and Context

Fixes: #5052

Description

Guard potentially undefined e_PAGE constant

How Has This Been Tested?

By manually running through the "How to Reproduce" steps in #5052

Types of Changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Performance enhancement (non-breaking change which improves efficiency)
• Code cleanup (non-breaking change which makes code smaller or more readable)
• Breaking change (fix or feature that would cause existing functionality to change)
• Documentation (a change to man pages or other documentation)

Checklist

• My code adheres to the e107 code style standard.
• I have read the contributing document.
• I have added tests to cover my changes.
• All new and existing tests pass.

[codeclimate]

Code Climate has analyzed commit 68b2401 and detected 1 issue on this pull request.

Here's the issue category breakdown:

Category	Count
Bug Risk	1

The test coverage on the diff in this pull request is 0.0% (80% is the threshold).

This pull request will bring the total coverage in the repository to 34.1% (-0.8% change).

View more on Code Climate.

[CaMer0n]

Thank you. Closed in favor of 5ff319c