protocols: fix client unit tests for go 1.13

The way to parse URLs in Go 1.13 has changed, now the `url.Parse` validates
that the port is only decimals, so the content of the error message when a
invalid port is used will change from "Invalid vsock port" to "invalid port",
hence the expected error message in the unit tests must change.

For more information about the change in Golang 1.13 see:
golang/go@61bb56a

fixes #772

Signed-off-by: Julio Montes <[email protected]>

protocols/client/client_test.go

@@ -131,7 +131,7 @@ func TestNewAgentClient(t *testing.T) {
 	cliFunc(mockBadSchemeAddr, false, "Invalid scheme:")
 	cliFunc(mockBadVsockScheme, false, "Invalid vsock scheme:")
 	cliFunc(mockVsockBadCid, false, "Invalid vsock cid")
-	cliFunc(mockVsockBadPort, false, "Invalid vsock port")
+	cliFunc(mockVsockBadPort, false, "invalid port")
 	cliFunc(mockFakeVsockAddr, false, "context deadline exceeded")
 
 	// wait mock server to stop
@@ -153,7 +153,7 @@ func TestNewAgentClientWithYamux(t *testing.T) {
 	cliFunc(mockBadSchemeAddr, false, "Invalid scheme:")
 	cliFunc(mockBadVsockScheme, false, "Invalid vsock scheme:")
 	cliFunc(mockVsockBadCid, false, "Invalid vsock cid")
-	cliFunc(mockVsockBadPort, false, "Invalid vsock port")
+	cliFunc(mockVsockBadPort, false, "invalid port")
 	cliFunc(mockFakeVsockAddr, false, "context deadline exceeded")
 
 	// wait mock server to stop