Bump gomatrixserverlib (#353)

* Bump gomatrixserverlib

Mostly because I want to use Erik's go-faster jsoning.

* Update KeyDB for new KeyFetcher API

we now need to implement FetcherName.

* Attempt to fix integ tests

CanonicalJSON doesn't like the empty string, apparently, and anyway
canonicalising it is pointless.

* More integ test fix

src/github.com/matrix-org/dendrite/cmd/mediaapi-integration-tests/main.go

@@ -239,7 +239,7 @@ func testDownload(host, origin, mediaID string, wantedStatusCode int, serverCmdC
 	testReq := &test.Request{
 		Req:              req,
 		WantedStatusCode: wantedStatusCode,
-		WantedBody:       test.CanonicalJSONInput([]string{""})[0],
+		WantedBody:       "",
 	}
 	testReq.Run(fmt.Sprintf("download mxc://%v/%v from %v", origin, mediaID, host), timeout, serverCmdChan)
 }
@@ -263,7 +263,7 @@ func testThumbnail(width, height int, resizeMethod, host string, serverCmdChan c
 	testReq := &test.Request{
 		Req:              req,
 		WantedStatusCode: 200,
-		WantedBody:       test.CanonicalJSONInput([]string{""})[0],
+		WantedBody:       "",
 	}
 	testReq.Run(fmt.Sprintf("thumbnail mxc://%v/%v%v from %v", testOrigin, testMediaID, query, host), timeout, serverCmdChan)
 }

src/github.com/matrix-org/dendrite/common/keydb/keydb.go

@@ -44,6 +44,11 @@ func NewDatabase(dataSourceName string) (*Database, error) {
 	return d, nil
 }
 
+// FetcherName implements KeyFetcher
+func (d Database) FetcherName() string {
+	return "KeyDatabase"
+}
+
 // FetchKeys implements gomatrixserverlib.KeyDatabase
 func (d *Database) FetchKeys(
 	ctx context.Context,