Partial Wipe Cache

[dzmitry.lahoda]

1. I mounted 1.tc with Cache passwords as removable medium
2. I mounted 2.tc with Cache passwords, forget to set removable medium.

Expected: I can somehow drop cache for 2.tc and remount it again with option as removable medium, or change mounting settings of 2.tc cause I use it with PKI software which reads keys only from removable media.
Actual: I have to press Wipe Cache. 1.tc, and any other volume data is lost. I have to remount all of them, but need only 2.tc.