Unable to replace plan in the plan repository setting

Problem Description
Before Bamboo 5.5, if you specify the Repository URL in the plan variable, and put that variable in the repository URL in the repository setting, it will be replaced just fine. However in Bamboo 5.5, you the variable won't be replaced. It will fail with this error (If you are using Subversion repository).

This is not a valid Subversion repository: svn: E125002: Malformed URL '${bamboo.myVariable}'

This issue won't happen in Global Variable.

Steps to replicate

1. Configure a plan variable in a plan configuration by going to Variables tab.
2. Let's make this variable called myVariable and put repository URL in there.
3. Configure the repository's URL in Repositories tab and put the following variable in Repository URL.

   ${bamboo.myVariable}
   

4. Configure the rest of the repository setting and save it.
5. Notice that it will fail with error mentioned which caused by the variable is not substituted.

Workaround
Use a global variable instead of plan level variable.