Fix the number of arguments expected by the server and client demos

On my subsequent branch that adds TCP, I added a second argument that is
the protocol to use. That's why these scripts currently expect 2
arguments. However, on _this_ branch, only the first argument is used,
and that first argument is the port. I ended up b0rking this when I
extracted this branch from the rest to make PR review easier.

This commit fixes it so that the scripts expect the correct number of
arguments, which is 1 argument, the port.

examples/basic_server/basic_server.go

@@ -75,7 +75,7 @@ func main() {
 
 	numArgs := len(os.Args[1:])
 
-	if numArgs != 2 {
+	if numArgs != 1 {
 		printUsage()
 		os.Exit(1)
 	}

examples/client/client.go

@@ -81,7 +81,7 @@ func main() {
 
 	numArgs := len(os.Args[1:])
 
-	if numArgs != 2 {
+	if numArgs != 1 {
 		printUsage()
 		os.Exit(1)
 	}