PHP 5.4 patch for the calendar module to stop offset warning

## Ready State: Yes

This pull request related to the following JIRA tickets:

[LDC-428: PHP Warning Errors: Illegal string offset 'data' in template_preprocess_calendar_month](https://imagex.atlassian.net/browse/LDC-428)

## Requirements & Dependencies

* No Requirements at this time.

## Deployment Instructions

* Merge code

## Usage/Test Instructions

* Adds calendar patch for the PHP 5.4 offset warning when viewing the editorial desk.