MediaScannerServiceTestCase : correct deprecated class reference.

libresonic-main/src/test/java/org/libresonic/player/service/MediaScannerServiceTestCase.java

@@ -3,8 +3,8 @@ package org.libresonic.player.service;
 import com.codahale.metrics.ConsoleReporter;
 import com.codahale.metrics.MetricRegistry;
 import com.codahale.metrics.Timer;
-import junit.framework.Assert;
 import org.apache.commons.io.IOUtils;
+import org.junit.Assert;
 import org.junit.ClassRule;
 import org.junit.Rule;
 import org.junit.Test;