Docs: Be ok with long recovery times

The _cat docs were asserting that an index took only some number of
milliseconds to recovery. In this build it took a whole second:
https://elasticsearch-ci.elastic.co/job/elastic+elasticsearch+5.3+multijob-intake/192/consoleFull

So this changes the assertion to be ok with a second.

docs/reference/cat/recovery.asciidoc

@@ -29,6 +29,7 @@ twitter 0     13ms store done  n/a         n/a         127.0.0.1   node-0      n
 // TESTRESPONSE[s/store/empty_store/]
 // TESTRESPONSE[s/100%/0.0%/]
 // TESTRESPONSE[s/9928/0/]
+// TESTRESPONSE[s/13ms/\\d+m?s/]
 // TESTRESPONSE[s/13/\\d+/ _cat]
 
 In the above case, the source and target nodes are the same because the recovery