Adjust skip version for shrink index test
This commit adjusts the skip version for a shrink index test that
ensures that a shrunken index ignores templates; the version can be
adjusted after the fix was backported targeting 5.6.0 and later.
Relates
---
"Shrink index ignores target template mapping":
- skip:
- version: " - 5.99.99"
+ version: " - 5.5.99"
reason: bug fixed in 6.0
- do:
