Deleting index with cryptic name metrics_%{_retention}_2015.11.13


i messed up a logstash config an created this nice index:

metrics_%{_retention} _2015.11.13

Trying to delete it gives me this output:

curl -XDELETE{_retention}_2015. 11.13
{"error":"IllegalArgumentException[invalid escape sequence `%r' at index 8 of metrics%_retention_2015.11.13]","status":500}

trying to escape it:

[root@prod00elastic12 wintelu]# curl -XDELETE{_retention}_201 5.11.13
{"error":"IllegalArgumentException[invalid escape sequence `%r' at index 8 of: metrics%_retention_2015.11.13]","status":500}

Is my only chance to disable the ''delete by name' setting and use wildcards, or is there another way to do so?