Upgrade go-common

vendor/git.autistici.org/ai3/go-common/clientutil/balancer.go

@@ -104,7 +104,10 @@ func (b *balancedBackend) Call(ctx context.Context, shard, path string, req, res
 	}
 
 	var tg targetGenerator = b.backendTracker
-	if b.sharded && shard != "" {
+	if b.sharded {
+		if shard == "" {
+			return fmt.Errorf("call without shard to sharded service %s", b.baseURI.String())
+		}
 		tg = newShardedGenerator(shard, b.baseURI.Host, b.resolver)
 	}
 	seq := newSequence(tg)

vendor/vendor.json

@@ -5,20 +5,20 @@
 		{
 			"checksumSHA1": "pLvPnUablirQucyALgrso9hLG4E=",
 			"path": "git.autistici.org/ai3/go-common",
-			"revision": "6916834dec86e761a3091c9628cbff9b6c389867",
-			"revisionTime": "2018-10-29T11:03:54Z"
+			"revision": "2fd6e256a27812c8dab4cce19b756213ce8c69bf",
+			"revisionTime": "2018-11-16T09:25:50Z"
 		},
 		{
-			"checksumSHA1": "Xd4ClmFykFMOg8b2ZFXimSS3Uj0=",
+			"checksumSHA1": "HtRAXnw4/i/jVoa5d3arp34Uerw=",
 			"path": "git.autistici.org/ai3/go-common/clientutil",
-			"revision": "6916834dec86e761a3091c9628cbff9b6c389867",
-			"revisionTime": "2018-10-29T11:03:54Z"
+			"revision": "2fd6e256a27812c8dab4cce19b756213ce8c69bf",
+			"revisionTime": "2018-11-16T09:25:50Z"
 		},
 		{
 			"checksumSHA1": "RyFydcBJvLBevfsriijLqHtZ0hs=",
 			"path": "git.autistici.org/ai3/go-common/serverutil",
-			"revision": "6916834dec86e761a3091c9628cbff9b6c389867",
-			"revisionTime": "2018-10-29T11:03:54Z"
+			"revision": "2fd6e256a27812c8dab4cce19b756213ce8c69bf",
+			"revisionTime": "2018-11-16T09:25:50Z"
 		},
 		{
 			"checksumSHA1": "rcWTaHvwTmKqbl8NqUF/nDsHzk8=",