add patch for 1.8.1 compatibility.

1.8.1 couchbase does not have the CouchAPIBase node attribute, therefore len(capiEpList) will always be zero.
This results in IsValid() returning false when config.bktType == BktTypeCouchbase. Instead, we should not
check the length of capiEpList as part of the validation of the routeconfig.

Change-Id: I4b0f5e0b0c43634b201f533524f54bc1c1c76794
Reviewed-on: http://review.couchbase.org/65060
Reviewed-by: Brett Lawson <brett19@gmail.com>
Tested-by: Brett Lawson <brett19@gmail.com>

gocbcore/routeconfig.go

@@ -41,7 +41,7 @@ func (config *routeConfig) IsValid() bool {
 	}
 	switch config.bktType {
 	case BktTypeCouchbase:
-		return len(config.vbMap) > 0 && len(config.vbMap[0]) > 0 && len(config.capiEpList) > 0
+		return len(config.vbMap) > 0 && len(config.vbMap[0]) > 0
 	case BktTypeMemcached:
 		return len(config.ketamaMap) > 0
 	default: