Only print PerformanceCounter statistics on destruction if there were any runs

modules/juce_core/time/juce_PerformanceCounter.cpp

@@ -43,7 +43,8 @@ PerformanceCounter::PerformanceCounter (const String& name, int runsPerPrintout,
 
 PerformanceCounter::~PerformanceCounter()
 {
-    printStatistics();
+    if (stats.numRuns > 0)
+        printStatistics();
 }
 
 PerformanceCounter::Statistics::Statistics() noexcept