docs: adjust reference path for php library

Because the path was changed in opentelemetry-php PR
open-telemetry/opentelemetry-php#1055

content/en/docs/instrumentation/php/manual.md

@@ -432,7 +432,7 @@ First, create a `MeterProvider`:
 ```php
 <?php
 
-use OpenTelemetry\Contrib\Otlp\ConsoleMetricExporterFactory;
+use OpenTelemetry\SDK\Metrics\MetricExporter\ConsoleMetricExporterFactory;
 use OpenTelemetry\SDK\Metrics\MeterProvider;
 use OpenTelemetry\SDK\Metrics\MetricReader\ExportingReader;