Colour by view options displays option ids when options are no longer available

Issue Summary

This is reproducible on Data Center: (yes)

ARJ has an issue with handling changes to the context of the custom field. The problem occurs when the user changes the context of the custom field and the project uses different options from a different context. When old options were used in the "colour by" feature then ARJ will display only ids, instead of names. ARJ should warn users about context changes or not available options should not be displayed at all. 

Steps to Reproduce

1. Create the project with 3 issues, e.g. called "Daj".
2. Create a stub project, e.g. called "Lol".
3. Create a plan with the above project as an issue source.
4. Create the custom field (type: "Select list", called: "Options") with some options e.g. "1_1", "2_2", "3_3" and assign both projects "Daj" and "Lol" to its context(called "Default context for Options").
   
5. Go to plan and add "Options" to the plan.
6. Assign each issue to one of the options.
7. Change view settings and pick "Colour By" to use "Options".
8. Add 3 colours and pick for each an option.
   
9. Save changes to Jira.
10. Go and create a new context(called: "Options Config other"), with some options and assign the "Daj" project to it.
    
11. Get back to plan and observe what happened to the "Colour By".

Expected Results

ARJ is able to handle no available options e.g warning, not displaying options.

Actual Results

ARJ displays ids of options that are not available

Workaround

1. Get back to the old context.
2. Remove from the "Colour By" options that are not longer used(those that are displayed with ids).