Fixed -Wunused-parameter warnings

plugins/samplemimo/testmosync/testmosync.cpp

@@ -155,6 +155,7 @@ const QString& TestMOSync::getDeviceDescription() const
 
 int TestMOSync::getSourceSampleRate(int index) const
 {
+    (void) index;
     return 0;
 }
 
@@ -424,4 +425,4 @@ void TestMOSync::webapiUpdateDeviceSettings(
     if (deviceSettingsKeys.contains("sampleRate")) {
         settings.m_sampleRate = response.getTestMoSyncSettings()->getSampleRate();
     }
-}
+}